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**files (2)**
– ## MOD003628Assignment2026.pdf
– Engineeringmanagementsystems.docx
**## MOD003628Assignment2026.pdf**
Module: Engineering Management Systems (MOD003628)
Submission Date: 17th April 2026
Weighting: 90% of Module assessment
Grading of the Assignment:
Any work extracted from texts must be clearly annotated as must all figures and diagrams.
The work must be referenced and be divided into suitable sections.
The typed report should be around 2,500 words (excluding tables).
Part Requirement Marks
Part 1. APL
Ltd Exercise APL Ltd MRP 20
Part 2.
Murray Rock
Drilling Ltd
Case Study
1. Identify and analyse the operational issues facing Murray Rock Drilling
Ltd. 15
2. Discuss the actions you would propose to improve delivery
performance and reduce lead time, (provide all the details, calculations
and justifications for your answer)
20
3. Build a Witness model of the traditional drills production system,
validate the model and comment on how the throughput could be
improved with minimal investment.
(Please look at the simulation notes at the bottom of the case study.)
25
4. With the world’s manufacturing move towards Industry 4.0, discuss
how Murray Rock Drilling Ltd could bring about further new
improvements in view of a move towards Industry 4.0.
10
Parts 1 & 2 Structure and presentation of report 10
Part 1: APL Ltd Exercise (20 marks)
APL has a demand of a total of 3,300 lamps to be delivered within the coming six months as in the
following table. Additionally, 1200 spare parts of Shell (item 219) are ordered for week 21. Determine the
planned order releases of the tube (item 186) and base insulator (item 222) showing all the steps.
Table 1: lamps orders to be delivered by APL in the next 6 months
Week 14 15 16 17 18 19 20 21 22 23 24 25 26
Due
Quantity 500 300 500 300 500 500 300 500
Table 2: Starting inventories and data for APL lamp production
Item (Item No.) Opening
Inventory Lot Size Safety Stock Lead time
(weeks)
Lamp (314) 0 Lot – 1
Socket Assembly (418) 700 1200 . 1
Shell (219) 2,800 4,000 . 2
Purchased tube (186) in ft. 3,000 12,000 3,000 8
Shell Insulation (220) 800 1,000 300 3
All other items (respective
units) 1000 1,000 5,000 1
Figure 1: APL lamp Bill of Materials
Part 2: The Murray Rock Drilling Ltd case study (80 marks)
The Murray Rock Drilling Ltd case study is attached. You are requested to read it, analyse it and respond
to the following requirements.
INTRODUCTION
Murray Rock Drilling Ltd is a subdivision of the Murray Engineering Group, part of the large conglomerate
PH Holdings PLC. Murray manufactures a range of machined steel products, designed to drill rock for
mining semi-precious ores and general quarrying. Murray shares certain functions with other parts of the
group, but it has its own production engineering, purchasing and production control functions. Murray's
Production Manager accepts sales orders from Quick Tools Ltd, the direct sales arm of Murray's, and from
two main customer s, Kerhandt (a German company, also a member of PH Holdings) and Barstrom (a large
international manufacturing and distribution group). Barstrom is Murray 's principal customer and
comprises 80 per cent of sales by volume.
The Murray manufacturing group has two production units located adjacent to one another. The main unit
produces around 90 per cent of output, concentrating on catalogue items with batch sizes of ten units or
more. The smaller unit concentrates on 'specials', bespoke tools and volumes of nine units or less. The
current lead time from order receipt to dispatch is in excess of twelve weeks. Management believes this to
be unacceptably high; a figure of six weeks should be achievable. One of the main areas o! concern is the
amount of time spent setting up the various machines between batches. Management believe that this is
primarily due to the wide range of products manufacture and the consequent small average batch size. The
Managing Director, Sid Beckett, feels that the introduction of group technology methods may help.
THE PRODUCT
The product range is basically a drill bit, usually called a tool, plus a range of drill rods, couplings, adaptors,
etc. The drill bits, shown generally in the Appendix, have two main features, a head and a shank and without
exception the tools are produced from steel bars and then turned/milled and heat-treated after which
carbide inserts are added to give the finished product. The carbide inserts may be of rectangular section,
which are brazed into position, or they may be small and cylindrical, which are inserted into circular holes
and retained by the interference fit between hole and carbide. Where rectangular type inserts are used only
two or four per tool are fitted, but where the cylindrical type are used the number may vary from 10 on a 50-
mm diameter tool to 120 on a 200-mm diameter tool. This latter type of bit accounts for 70 per cent of
production and is called a button bit whilst the other is called a cross bit and is a more traditional design.
The product range, whilst limited in its geometric variations Is very large with some 1,000 catalogue items
to which must be added a wide variety of specials to suit particular needs. The grade of carbide, number
and pattern of buttons, design of flushing hole, etc. are all varied to enable the tool to perform better in
varying geological conditions. Thus, in reality the product range consists of 2,000 to 3,000 items.
The variations are:
• Shank types:
o Splined: 4 types; Head diameter range 115-200 mm
o Threaded: 6 types; Head diameter range 46-100 mm
• Head diameters: Range 38-200 mm; Number of diameters 42
• Carbide grades: 4 ;
• Steel types: 1
THE MANUFACTURING PROCESS
The process is predominantly a flow batch process. The vast majority of the product range, tools, follow
virtually identical routes (see Appendix). Set-up time accounts for approximately 26 per cent of capacity of
the machines. Keeping set-ups to a minimum is currently achieved by both grouping identical product
orders together to form larger batch sizes and using the current set-up on any machine as a sequencing
guide, that is do all the jobs that require the same setting first and then change the setting.
MANUFACTURING FACILITIES
Murray recently purchased most of the machines from Barstrom's old plant in Bristol. The transfer of the
machines took three months. Some machines are still not in their final positions, and a number are still
giving problems – one grinding machine has never run properly. This resulted in a substantial increase in
the number of employees, the number of machines to be operated, the volume of the material to be
processed and the complexity of the whole operation. The layout of the machines is consistent with the
stages of the manufacturing process. Infrastructure, such as industrial engineers, maintenance, plant
engineers, accounts, etc. is shared with other parts of the group.
MANUFACTURING STRATEGY
Murray believes that their competitive advantage in tool-bit manufacturing lies in the price at which they
can provide a wide range of tool-bit products. Their strategy is to use economies of ·scale to achieve lower
costs. To this end, they have created a small plant within plant to produce low volume items (less than ten
off), allowing the main plant to concentrate on the higher volume orders. Hard state operations, however,
were all grouped together.
BARSTROM AGREEMENT
Barstrom used to have their own production facility in Bristol but closed it in favour of a sole supplier
agreement with Murray for a substantial discount on list price. The agreement on order quantities is that
the minimum order quantity should be thirty units, unless annual demand is less than thirty, in which case
the minimum quantity is twelve units. Approximately 40 per cent of orders are for the minimum quantity of
twelve. However, there are many instances where a series of orders for twelve off have been placed in
consecutive months for the same product. Therefore, there is room for improvement at Barstrom. Orders
are processed on a make-to- order basis and usually go into stock at Barstrom.
QUICK TOOLS LTD
Although part of Murray Group, Quick Tools Ltd is run as a separate company. Order intake at Quick Tools
is handled separately and delivery dates are quoted by Quick Tools salesmen without reference to Murray
where the parts are manufactured.
The standard lead time for Quick Tools orders is only eight weeks, because work pack drawings and route
cards are put together by Quick Tools and are ready for loading at Murray.
INVESTIGATION OF LEAD TIME
The Managing Director
'Our biggest problem here is the amount of time spent setting up.' complained Sid Beckett, the new MD of
Murray. 'Our average batch size is only thirty bodies. If only we could reduce the set-up times and introduce
cellular manufacturing, the released capacity could be used to shift all this inventory faster and bring our
lead times down.' Commenting on the high level of WIP, Beckett stated that the latest report suggested
around 10,000 bodies and added, 'We've not been reaching our output targets recently. We were aiming for
1,000bodies per week but only seem to be managing around 700. You should have seen the WIP inventory
earlier in the year, we were up to our waists in the stuff!' Asked if sales had been bit by the recession yet,
Beckett commented that Murray sales this month were down on the previous months, but it was difficult
to say whether or not this was due to the recession. Commenting on the twelve weeks quoted lead time,
Beckett informed: 'Some jobs are still here after four or five months but, usually, they are non- urgent jobs.
We can push a job through in just over a week when we have to. But, in general, most jobs are going through
in twelve weeks, two to three weeks in the office and nine to ten weeks on the shop floor.' 'We use a
standard costing system, so we do not really know what each item costs because we do not have a
standard set-up time. Standards are only calculated for run times. We are having our costing system looked
at by our accountant$. They are due to report in a couple of months. 'Lost time can be determined from the
operators' time sheets. Scrap and rework are recorded each day in the Inspection logbook. Inspection also
log the work going to and from subcontractors and into stores.
The Production and Materials Controller
The WIP report produced on the computer system was out of date and not regarded as reliable by any of
the staff, including Fred Pearse, the Production and Materials Controller (PMC): 'Many of the entries for
batches of one and two units are items which have been scrapped but not yet taken off the system. Also,
some of the items on the list have been dispatched but the records have not worked their way through the
system yet.' Overall, the computer report overestimates WIP by about 10 %.
The report was produced weekly and comprised a list of part numbers with quantities sorted by due date
and then by location. For example:
Due Date Location Part No. Description Quantity
Week 17 Off Soft State 972364222 150 DTH Spline 2
It was normally only printed out for due dates which had already passed. It was, therefore, being produced
to monitor arrears rather than to monitor material flow through the plant. Maintaining delivery performance
proved to be a difficult task, which required a special exercise to be carried out. When asked about a record
of lost time, Pearse replied that the Senior Foreman kept the operator time sheets and that they would
contain that sort of data but that he did not monitor lost time: 'The Industrial Engineers occasionally
monitor it. As for scrap and rework, that is monitored. Speak to Phil Johnson, the Production Manager, he
has the figures.
The Production Manager
On receipt of order enquiries from Barstrom, Kenhandt or Quick Tools, a 'due date' would be issued in line
with capacity and the order entered into a register by due date. Over a period of three to four weeks, the
register would be checked for orders of identical part numbers and, where found, a single larger batch
created. This would then be issued to the shop floor.
'lt would probably take about forty-eight hours to machine an average tool, if you include set-ups, but that
would be for an average batch, which is around thirty bodies,' commented Phil Johnson, the Production
Manager. Asked about capacity calculations, Johnson said: 'From our dispatch figures, it would appear that
our capacity is around 800bodies per week at present. Prior to the Barstrom deal, we were making around
700 per week. We should be capable of reaching 1,000 per week but some of the foremen aren't pulling
their weight and some of the new machines aren't capable of producing what Barstrom said they would.
“We've had a lot of trouble with the machines we bought from Barstrom. They have been breaking down a
lot and we have been unable to reach the output levels we expected. Also, we are short of setter operators,
so some of the younger lads have to wait for a setter operator before they can proceed with their set-up. A
·few months ago, we also had a problem with a shortage of inspectors, but we have solved this by reducing
the amount of inspection required. During the early months of the year, when we were installing the new
machines, we had higher than usual scrap and rework levels, but this is now under control”.
Capacity Calculation
It was possible to analyse the output history of both of the main sections of the plant (Soft State and Hard
State). The Inspection Logbook logged jobs out of Soft State to heat treatment and shotblast, and they were
also logged out of Hard State to Inspection and then to Stores. The average through-put for Hard State, that
is logged to Stores, was around 700 bodies per week – less than the figure of 800 quoted by Phil Johnson.
At no point had output reached 1,000 bodies per week. Appendix 3 was prepared to show the machine
hours needed for an average batch size of twenty-six in soft machining and an average batch size of twenty-
three in hard machining. These were based on an analysis of the route cards of the most common products,
covering 80 per cent of the previous eight months' output and some supporting data.
The average batch size in Hard State is lower, due to the inclusion of the small batches from the low volume
plant.
Shop floor scheduling
Shop floor scheduling was carried out by looking first at the set-up of a particular machine and then at the
requirements of the various jobs in the queue. If there was a job with similar set-up requirements close to
the front of the queue, it would be pulled forward. If not, the next job in sequence was loaded and the
machine re-set. The due dates on the route card were often no help to the foremen, since they had often
expired. In the foremen's office was a large board with 'T'-cards slotted into it for each batch going through
the plant. These cards were inserted under the particular machine heading at the top of the board and had
the dispatch date for the batch marked on the card.
The foremen had no information on what works orders were going to be released next and only the 'T'-card
board information on which jobs were waiting upstream of Hard State. The sequence of work the foremen
had given to the machine operators was frequently changed by instructions given by the MD and Production
Manager. These instructions were usually issued in response to calls from customers trying to expedite
overdue orders.
Asked about the lack of Information, the foremen agreed the system was chaotic, but what could they do?
The Hard State Foreman mentioned that previously they used a report which listed the complete WIP
inventory. by plant section, subcontracted activities, etc. but had stopped using it because it was so
unreliable, and anyway priorities were always being altered. So now they just planned from day to day using
due dates as a basis and tried to reduce the number of set-ups where they could.
Sales discipline
Sales were received in two ways. First, Barstrom would send an order to the Production Manager each
week. He would allocate a date by which the work could be completed. ln theory, this was based on a
twelve-week lead time plus or minus a few weeks, depending on the quantity of tool-holders due for delivery
at that time. The same approach was used for Kerhandt orders. Second, Quick Tools would top up the
Barstrom orders if they could or raise an additional order for those products not ordered by Barstrom. Quick
Tools were supposed to be supplying their customers from stock, but this was often not possible because
of shortages. Thus, many of the Quick Tools orders were required by customers as soon as possible. lf a
competitive delivery time could not be given, the customer would often phone around for a faster delivery
This prompted the salesmen to quote unrealistic delivery dates in the hope that Production would rush
them through: 'Oh, but we can't turn down £6,000s' worth of business because they wanted delivery in four
weeks. I know that is less than the normal lead time, but if we push it through, we can make the due date.
Anyway, we can't afford to refuse important customers. If we don't have the stock, we have to rush it
through.' Phil Johnson often accepted this situation, and this resulted in orders going through with due
dates that were impossible to achieve or had even passed.
An analysis of orders received against bodies logged to stores (the nearest measurement available to
orders dispatched) showed that there was virtually no correlation between the two, even allowing for a
twelve-week or longer lead time. By physically counting the WIP on the shop floor and extrapolating the
order input/output data back to the beginning of the year, historical WIP inventory and order backlog could
be plotted (see figure below). (Due to the lack of any records of works order releases to the shopfloor, Soft
State WlP inventory cannot be separated from the order backlog.)
Lead time
With a measure of capacity and WIP Inventory, it was now possible to make an estimate of manufacturing
lead time. By making a rough assumption that the through-put of 800 bodies per week was the same for
each machining stage in Soft State and 700 per week for each Hard State stage, the lead time broke down
to roughly four weeks' administrative lead time (office processing and hatching up) plus nine weeks'
manufacturing lead time. Eighty per cent of the manufacturing lead time was due to queueing and 75 per
cent of the administrative lead time due to the practice of delaying works order releases in the hope of
creating larger batches.
Final assembly
Another area where lead time was increased was in final assembly. Finished bodies were often delayed
due to the lack of carbide inserts and packaging materials. The system employed was for the PMC to order
the bought-in parts when ordering· the raw material for the bodies and to place works orders for any in-
house components at the same time as placing the works order for the bodies themselves. Often the
quantities were small and therefore the placement of the orders would be delayed to increase the order
size – and occasionally forgotten or lost. The same often applied to in-house· works orders.
The information system
Information was gathered and passed on by several individuals: the Managing Director, the Production
Manager, the PMC and the Senior Foreman. All did so separately, on hand-written sheets of paper which
they used at progress meetings. The PMC used computer system reports, but system data were not kept
up to date. No one had definitive information and even when the Managing Director passed photocopies of
his sheets round, no sooner where they Issued than they were changed. In effect, Murray had no single
systematic method of processing the information necessary to run the factory effectively.
Figure 2: BareStrom Late Deliveries Distribution
Figure 3: Alternative shank styles for rock drills
Table 3: set-up times, run times, manning levels and machine hours
Notes: Table 3 uses the available data for set-up times, run times, manning levels and machine hours,
available to calculate the machine loading factors at each stage of the process. The average through-put
of the Hard State is around 700 bodies/week, significantly lower than the 1,000 bodies/week the company
would like to achieve. Weighted average run times were averaged from product route cards weighted in
accordance with the volumes produced of each product over the previous eight months. A day or night
shift is thirty-nine hours per week. Overtime amounted to four hours per week.
Figure 4: Manufacturing Process flow for Button and Taper Socket rock drills
Assumptions and considerations for Modelling of the Murray System
Please read the following assumptions before you attempt to model the process of this case
study.
Main Assumptions:
1. Simulation is to consider only the "Splined type" and the "Threaded type" drills;
2. There are only a total of 4 milling machines and 4 turning machines. The quantity of other
machines is to be reasonably selected based on this.
3. For the original model, the lot sizes of both soft state and hard state are 26. The current output
as per the company data is around 700 bodies/ week but Murray would like to raise the output to
1000/week with minimal cost.
4. The original setting follows a functional (process) layout as it is a batch process. Similar
machines are positioned together as a centre (such as a milling centre). Same machine types
will only be split if similar consecutive operations must be done by the same type of machine.
For example, the turning machines could be split into two adjacent stations of 2 lathes each to
accommodate the consecutive ''Turn" operations at the beginning of the process.
5. You can add buffers of capacity up to 7 between stations, as appropriate.
Note: where there are cyclic flows of parts (returning parts) remember to give priority to the more
advanced parts. This helps to avoid clogging.
The first step on this project would be to produce a diagram with a functional layout showing the
flow of parts clearly.
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**## MOD003628Assignment2026.pdf**
Module: Engineering Management Systems (MOD003628)
Submission Date: 17th April 2026
Weighting: 90% of Module assessment
Grading of the Assignment:
Any work extracted from texts must be clearly annotated as must all figures and diagrams.
The work must be referenced and be divided into suitable sections.
The typed report should be around 2,500 words (excluding tables).
Part Requirement Marks
Part 1. APL
Ltd Exercise APL Ltd MRP 20
Part 2.
Murray Rock
Drilling Ltd
Case Study
1. Identify and analyse the operational issues facing Murray Rock Drilling
Ltd. 15
2. Discuss the actions you would propose to improve delivery
performance and reduce lead time, (provide all the details, calculations
and justifications for your answer)
20
3. Build a Witness model of the traditional drills production system,
validate the model and comment on how the throughput could be
improved with minimal investment.
(Please look at the simulation notes at the bottom of the case study.)
25
4. With the world’s manufacturing move towards Industry 4.0, discuss
how Murray Rock Drilling Ltd could bring about further new
improvements in view of a move towards Industry 4.0.
10
Parts 1 & 2 Structure and presentation of report 10
Part 1: APL Ltd Exercise (20 marks)
APL has a demand of a total of 3,300 lamps to be delivered within the coming six months as in the
following table. Additionally, 1200 spare parts of Shell (item 219) are ordered for week 21. Determine the
planned order releases of the tube (item 186) and base insulator (item 222) showing all the steps.
Table 1: lamps orders to be delivered by APL in the next 6 months
Week 14 15 16 17 18 19 20 21 22 23 24 25 26
Due
Quantity 500 300 500 300 500 500 300 500
Table 2: Starting inventories and data for APL lamp production
Item (Item No.) Opening
Inventory Lot Size Safety Stock Lead time
(weeks)
Lamp (314) 0 Lot – 1
Socket Assembly (418) 700 1200 . 1
Shell (219) 2,800 4,000 . 2
Purchased tube (186) in ft. 3,000 12,000 3,000 8
Shell Insulation (220) 800 1,000 300 3
All other items (respective
units) 1000 1,000 5,000 1
Figure 1: APL lamp Bill of Materials
Part 2: The Murray Rock Drilling Ltd case study (80 marks)
The Murray Rock Drilling Ltd case study is attached. You are requested to read it, analyse it and respond
to the following requirements.
INTRODUCTION
Murray Rock Drilling Ltd is a subdivision of the Murray Engineering Group, part of the large conglomerate
PH Holdings PLC. Murray manufactures a range of machined steel products, designed to drill rock for
mining semi-precious ores and general quarrying. Murray shares certain functions with other parts of the
group, but it has its own production engineering, purchasing and production control functions. Murray's
Production Manager accepts sales orders from Quick Tools Ltd, the direct sales arm of Murray's, and from
two main customer s, Kerhandt (a German company, also a member of PH Holdings) and Barstrom (a large
international manufacturing and distribution group). Barstrom is Murray 's principal customer and
comprises 80 per cent of sales by volume.
The Murray manufacturing group has two production units located adjacent to one another. The main unit
produces around 90 per cent of output, concentrating on catalogue items with batch sizes of ten units or
more. The smaller unit concentrates on 'specials', bespoke tools and volumes of nine units or less. The
current lead time from order receipt to dispatch is in excess of twelve weeks. Management believes this to
be unacceptably high; a figure of six weeks should be achievable. One of the main areas o! concern is the
amount of time spent setting up the various machines between batches. Management believe that this is
primarily due to the wide range of products manufacture and the consequent small average batch size. The
Managing Director, Sid Beckett, feels that the introduction of group technology methods may help.
THE PRODUCT
The product range is basically a drill bit, usually called a tool, plus a range of drill rods, couplings, adaptors,
etc. The drill bits, shown generally in the Appendix, have two main features, a head and a shank and without
exception the tools are produced from steel bars and then turned/milled and heat-treated after which
carbide inserts are added to give the finished product. The carbide inserts may be of rectangular section,
which are brazed into position, or they may be small and cylindrical, which are inserted into circular holes
and retained by the interference fit between hole and carbide. Where rectangular type inserts are used only
two or four per tool are fitted, but where the cylindrical type are used the number may vary from 10 on a 50-
mm diameter tool to 120 on a 200-mm diameter tool. This latter type of bit accounts for 70 per cent of
production and is called a button bit whilst the other is called a cross bit and is a more traditional design.
The product range, whilst limited in its geometric variations Is very large with some 1,000 catalogue items
to which must be added a wide variety of specials to suit particular needs. The grade of carbide, number
and pattern of buttons, design of flushing hole, etc. are all varied to enable the tool to perform better in
varying geological conditions. Thus, in reality the product range consists of 2,000 to 3,000 items.
The variations are:
• Shank types:
o Splined: 4 types; Head diameter range 115-200 mm
o Threaded: 6 types; Head diameter range 46-100 mm
• Head diameters: Range 38-200 mm; Number of diameters 42
• Carbide grades: 4 ;
• Steel types: 1
THE MANUFACTURING PROCESS
The process is predominantly a flow batch process. The vast majority of the product range, tools, follow
virtually identical routes (see Appendix). Set-up time accounts for approximately 26 per cent of capacity of
the machines. Keeping set-ups to a minimum is currently achieved by both grouping identical product
orders together to form larger batch sizes and using the current set-up on any machine as a sequencing
guide, that is do all the jobs that require the same setting first and then change the setting.
MANUFACTURING FACILITIES
Murray recently purchased most of the machines from Barstrom's old plant in Bristol. The transfer of the
machines took three months. Some machines are still not in their final positions, and a number are still
giving problems – one grinding machine has never run properly. This resulted in a substantial increase in
the number of employees, the number of machines to be operated, the volume of the material to be
processed and the complexity of the whole operation. The layout of the machines is consistent with the
stages of the manufacturing process. Infrastructure, such as industrial engineers, maintenance, plant
engineers, accounts, etc. is shared with other parts of the group.
MANUFACTURING STRATEGY
Murray believes that their competitive advantage in tool-bit manufacturing lies in the price at which they
can provide a wide range of tool-bit products. Their strategy is to use economies of ·scale to achieve lower
costs. To this end, they have created a small plant within plant to produce low volume items (less than ten
off), allowing the main plant to concentrate on the higher volume orders. Hard state operations, however,
were all grouped together.
BARSTROM AGREEMENT
Barstrom used to have their own production facility in Bristol but closed it in favour of a sole supplier
agreement with Murray for a substantial discount on list price. The agreement on order quantities is that
the minimum order quantity should be thirty units, unless annual demand is less than thirty, in which case
the minimum quantity is twelve units. Approximately 40 per cent of orders are for the minimum quantity of
twelve. However, there are many instances where a series of orders for twelve off have been placed in
consecutive months for the same product. Therefore, there is room for improvement at Barstrom. Orders
are processed on a make-to- order basis and usually go into stock at Barstrom.
QUICK TOOLS LTD
Although part of Murray Group, Quick Tools Ltd is run as a separate company. Order intake at Quick Tools
is handled separately and delivery dates are quoted by Quick Tools salesmen without reference to Murray
where the parts are manufactured.
The standard lead time for Quick Tools orders is only eight weeks, because work pack drawings and route
cards are put together by Quick Tools and are ready for loading at Murray.
INVESTIGATION OF LEAD TIME
The Managing Director
'Our biggest problem here is the amount of time spent setting up.' complained Sid Beckett, the new MD of
Murray. 'Our average batch size is only thirty bodies. If only we could reduce the set-up times and introduce
cellular manufacturing, the released capacity could be used to shift all this inventory faster and bring our
lead times down.' Commenting on the high level of WIP, Beckett stated that the latest report suggested
around 10,000 bodies and added, 'We've not been reaching our output targets recently. We were aiming for
1,000bodies per week but only seem to be managing around 700. You should have seen the WIP inventory
earlier in the year, we were up to our waists in the stuff!' Asked if sales had been bit by the recession yet,
Beckett commented that Murray sales this month were down on the previous months, but it was difficult
to say whether or not this was due to the recession. Commenting on the twelve weeks quoted lead time,
Beckett informed: 'Some jobs are still here after four or five months but, usually, they are non- urgent jobs.
We can push a job through in just over a week when we have to. But, in general, most jobs are going through
in twelve weeks, two to three weeks in the office and nine to ten weeks on the shop floor.' 'We use a
standard costing system, so we do not really know what each item costs because we do not have a
standard set-up time. Standards are only calculated for run times. We are having our costing system looked
at by our accountant$. They are due to report in a couple of months. 'Lost time can be determined from the
operators' time sheets. Scrap and rework are recorded each day in the Inspection logbook. Inspection also
log the work going to and from subcontractors and into stores.
The Production and Materials Controller
The WIP report produced on the computer system was out of date and not regarded as reliable by any of
the staff, including Fred Pearse, the Production and Materials Controller (PMC): 'Many of the entries for
batches of one and two units are items which have been scrapped but not yet taken off the system. Also,
some of the items on the list have been dispatched but the records have not worked their way through the
system yet.' Overall, the computer report overestimates WIP by about 10 %.
The report was produced weekly and comprised a list of part numbers with quantities sorted by due date
and then by location. For example:
Due Date Location Part No. Description Quantity
Week 17 Off Soft State 972364222 150 DTH Spline 2
It was normally only printed out for due dates which had already passed. It was, therefore, being produced
to monitor arrears rather than to monitor material flow through the plant. Maintaining delivery performance
proved to be a difficult task, which required a special exercise to be carried out. When asked about a record
of lost time, Pearse replied that the Senior Foreman kept the operator time sheets and that they would
contain that sort of data but that he did not monitor lost time: 'The Industrial Engineers occasionally
monitor it. As for scrap and rework, that is monitored. Speak to Phil Johnson, the Production Manager, he
has the figures.
The Production Manager
On receipt of order enquiries from Barstrom, Kenhandt or Quick Tools, a 'due date' would be issued in line
with capacity and the order entered into a register by due date. Over a period of three to four weeks, the
register would be checked for orders of identical part numbers and, where found, a single larger batch
created. This would then be issued to the shop floor.
'lt would probably take about forty-eight hours to machine an average tool, if you include set-ups, but that
would be for an average batch, which is around thirty bodies,' commented Phil Johnson, the Production
Manager. Asked about capacity calculations, Johnson said: 'From our dispatch figures, it would appear that
our capacity is around 800bodies per week at present. Prior to the Barstrom deal, we were making around
700 per week. We should be capable of reaching 1,000 per week but some of the foremen aren't pulling
their weight and some of the new machines aren't capable of producing what Barstrom said they would.
“We've had a lot of trouble with the machines we bought from Barstrom. They have been breaking down a
lot and we have been unable to reach the output levels we expected. Also, we are short of setter operators,
so some of the younger lads have to wait for a setter operator before they can proceed with their set-up. A
·few months ago, we also had a problem with a shortage of inspectors, but we have solved this by reducing
the amount of inspection required. During the early months of the year, when we were installing the new
machines, we had higher than usual scrap and rework levels, but this is now under control”.
Capacity Calculation
It was possible to analyse the output history of both of the main sections of the plant (Soft State and Hard
State). The Inspection Logbook logged jobs out of Soft State to heat treatment and shotblast, and they were
also logged out of Hard State to Inspection and then to Stores. The average through-put for Hard State, that
is logged to Stores, was around 700 bodies per week – less than the figure of 800 quoted by Phil Johnson.
At no point had output reached 1,000 bodies per week. Appendix 3 was prepared to show the machine
hours needed for an average batch size of twenty-six in soft machining and an average batch size of twenty-
three in hard machining. These were based on an analysis of the route cards of the most common products,
covering 80 per cent of the previous eight months' output and some supporting data.
The average batch size in Hard State is lower, due to the inclusion of the small batches from the low volume
plant.
Shop floor scheduling
Shop floor scheduling was carried out by looking first at the set-up of a particular machine and then at the
requirements of the various jobs in the queue. If there was a job with similar set-up requirements close to
the front of the queue, it would be pulled forward. If not, the next job in sequence was loaded and the
machine re-set. The due dates on the route card were often no help to the foremen, since they had often
expired. In the foremen's office was a large board with 'T'-cards slotted into it for each batch going through
the plant. These cards were inserted under the particular machine heading at the top of the board and had
the dispatch date for the batch marked on the card.
The foremen had no information on what works orders were going to be released next and only the 'T'-card
board information on which jobs were waiting upstream of Hard State. The sequence of work the foremen
had given to the machine operators was frequently changed by instructions given by the MD and Production
Manager. These instructions were usually issued in response to calls from customers trying to expedite
overdue orders.
Asked about the lack of Information, the foremen agreed the system was chaotic, but what could they do?
The Hard State Foreman mentioned that previously they used a report which listed the complete WIP
inventory. by plant section, subcontracted activities, etc. but had stopped using it because it was so
unreliable, and anyway priorities were always being altered. So now they just planned from day to day using
due dates as a basis and tried to reduce the number of set-ups where they could.
Sales discipline
Sales were received in two ways. First, Barstrom would send an order to the Production Manager each
week. He would allocate a date by which the work could be completed. ln theory, this was based on a
twelve-week lead time plus or minus a few weeks, depending on the quantity of tool-holders due for delivery
at that time. The same approach was used for Kerhandt orders. Second, Quick Tools would top up the
Barstrom orders if they could or raise an additional order for those products not ordered by Barstrom. Quick
Tools were supposed to be supplying their customers from stock, but this was often not possible because
of shortages. Thus, many of the Quick Tools orders were required by customers as soon as possible. lf a
competitive delivery time could not be given, the customer would often phone around for a faster delivery
This prompted the salesmen to quote unrealistic delivery dates in the hope that Production would rush
them through: 'Oh, but we can't turn down £6,000s' worth of business because they wanted delivery in four
weeks. I know that is less than the normal lead time, but if we push it through, we can make the due date.
Anyway, we can't afford to refuse important customers. If we don't have the stock, we have to rush it
through.' Phil Johnson often accepted this situation, and this resulted in orders going through with due
dates that were impossible to achieve or had even passed.
An analysis of orders received against bodies logged to stores (the nearest measurement available to
orders dispatched) showed that there was virtually no correlation between the two, even allowing for a
twelve-week or longer lead time. By physically counting the WIP on the shop floor and extrapolating the
order input/output data back to the beginning of the year, historical WIP inventory and order backlog could
be plotted (see figure below). (Due to the lack of any records of works order releases to the shopfloor, Soft
State WlP inventory cannot be separated from the order backlog.)
Lead time
With a measure of capacity and WIP Inventory, it was now possible to make an estimate of manufacturing
lead time. By making a rough assumption that the through-put of 800 bodies per week was the same for
each machining stage in Soft State and 700 per week for each Hard State stage, the lead time broke down
to roughly four weeks' administrative lead time (office processing and hatching up) plus nine weeks'
manufacturing lead time. Eighty per cent of the manufacturing lead time was due to queueing and 75 per
cent of the administrative lead time due to the practice of delaying works order releases in the hope of
creating larger batches.
Final assembly
Another area where lead time was increased was in final assembly. Finished bodies were often delayed
due to the lack of carbide inserts and packaging materials. The system employed was for the PMC to order
the bought-in parts when ordering· the raw material for the bodies and to place works orders for any in-
house components at the same time as placing the works order for the bodies themselves. Often the
quantities were small and therefore the placement of the orders would be delayed to increase the order
size – and occasionally forgotten or lost. The same often applied to in-house· works orders.
The information system
Information was gathered and passed on by several individuals: the Managing Director, the Production
Manager, the PMC and the Senior Foreman. All did so separately, on hand-written sheets of paper which
they used at progress meetings. The PMC used computer system reports, but system data were not kept
up to date. No one had definitive information and even when the Managing Director passed photocopies of
his sheets round, no sooner where they Issued than they were changed. In effect, Murray had no single
systematic method of processing the information necessary to run the factory effectively.
Figure 2: BareStrom Late Deliveries Distribution
Figure 3: Alternative shank styles for rock drills
Table 3: set-up times, run times, manning levels and machine hours
Notes: Table 3 uses the available data for set-up times, run times, manning levels and machine hours,
available to calculate the machine loading factors at each stage of the process. The average through-put
of the Hard State is around 700 bodies/week, significantly lower than the 1,000 bodies/week the company
would like to achieve. Weighted average run times were averaged from product route cards weighted in
accordance with the volumes produced of each product over the previous eight months. A day or night
shift is thirty-nine hours per week. Overtime amounted to four hours per week.
Figure 4: Manufacturing Process flow for Button and Taper Socket rock drills
Assumptions and considerations for Modelling of the Murray System
Please read the following assumptions before you attempt to model the process of this case
study.
Main Assumptions:
1. Simulation is to consider only the "Splined type" and the "Threaded type" drills;
2. There are only a total of 4 milling machines and 4 turning machines. The quantity of other
machines is to be reasonably selected based on this.
3. For the original model, the lot sizes of both soft state and hard state are 26. The current output
as per the company data is around 700 bodies/ week but Murray would like to raise the output to
1000/week with minimal cost.
4. The original setting follows a functional (process) layout as it is a batch process. Similar
machines are positioned together as a centre (such as a milling centre). Same machine types
will only be split if similar consecutive operations must be done by the same type of machine.
For example, the turning machines could be split into two adjacent stations of 2 lathes each to
accommodate the consecutive ''Turn" operations at the beginning of the process.
5. You can add buffers of capacity up to 7 between stations, as appropriate.
Note: where there are cyclic flows of parts (returning parts) remember to give priority to the more
advanced parts. This helps to avoid clogging.
The first step on this project would be to produce a diagram with a functional layout showing the
flow of parts clearly.
**Engineeringmanagementsystems.docx**
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**## MOD003628Assignment2026.pdf**
Module: Engineering Management Systems (MOD003628)
Submission Date: 17th April 2026
Weighting: 90% of Module assessment
Grading of the Assignment:
Any work extracted from texts must be clearly annotated as must all figures and diagrams.
The work must be referenced and be divided into suitable sections.
The typed report should be around 2,500 words (excluding tables).
Part Requirement Marks
Part 1. APL
Ltd Exercise APL Ltd MRP 20
Part 2.
Murray Rock
Drilling Ltd
Case Study
1. Identify and analyse the operational issues facing Murray Rock Drilling
Ltd. 15
2. Discuss the actions you would propose to improve delivery
performance and reduce lead time, (provide all the details, calculations
and justifications for your answer)
20
3. Build a Witness model of the traditional drills production system,
validate the model and comment on how the throughput could be
improved with minimal investment.
(Please look at the simulation notes at the bottom of the case study.)
25
4. With the world’s manufacturing move towards Industry 4.0, discuss
how Murray Rock Drilling Ltd could bring about further new
improvements in view of a move towards Industry 4.0.
10
Parts 1 & 2 Structure and presentation of report 10
Part 1: APL Ltd Exercise (20 marks)
APL has a demand of a total of 3,300 lamps to be delivered within the coming six months as in the
following table. Additionally, 1200 spare parts of Shell (item 219) are ordered for week 21. Determine the
planned order releases of the tube (item 186) and base insulator (item 222) showing all the steps.
Table 1: lamps orders to be delivered by APL in the next 6 months
Week 14 15 16 17 18 19 20 21 22 23 24 25 26
Due
Quantity 500 300 500 300 500 500 300 500
Table 2: Starting inventories and data for APL lamp production
Item (Item No.) Opening
Inventory Lot Size Safety Stock Lead time
(weeks)
Lamp (314) 0 Lot – 1
Socket Assembly (418) 700 1200 . 1
Shell (219) 2,800 4,000 . 2
Purchased tube (186) in ft. 3,000 12,000 3,000 8
Shell Insulation (220) 800 1,000 300 3
All other items (respective
units) 1000 1,000 5,000 1
Figure 1: APL lamp Bill of Materials
Part 2: The Murray Rock Drilling Ltd case study (80 marks)
The Murray Rock Drilling Ltd case study is attached. You are requested to read it, analyse it and respond
to the following requirements.
INTRODUCTION
Murray Rock Drilling Ltd is a subdivision of the Murray Engineering Group, part of the large conglomerate
PH Holdings PLC. Murray manufactures a range of machined steel products, designed to drill rock for
mining semi-precious ores and general quarrying. Murray shares certain functions with other parts of the
group, but it has its own production engineering, purchasing and production control functions. Murray's
Production Manager accepts sales orders from Quick Tools Ltd, the direct sales arm of Murray's, and from
two main customer s, Kerhandt (a German company, also a member of PH Holdings) and Barstrom (a large
international manufacturing and distribution group). Barstrom is Murray 's principal customer and
comprises 80 per cent of sales by volume.
The Murray manufacturing group has two production units located adjacent to one another. The main unit
produces around 90 per cent of output, concentrating on catalogue items with batch sizes of ten units or
more. The smaller unit concentrates on 'specials', bespoke tools and volumes of nine units or less. The
current lead time from order receipt to dispatch is in excess of twelve weeks. Management believes this to
be unacceptably high; a figure of six weeks should be achievable. One of the main areas o! concern is the
amount of time spent setting up the various machines between batches. Management believe that this is
primarily due to the wide range of products manufacture and the consequent small average batch size. The
Managing Director, Sid Beckett, feels that the introduction of group technology methods may help.
THE PRODUCT
The product range is basically a drill bit, usually called a tool, plus a range of drill rods, couplings, adaptors,
etc. The drill bits, shown generally in the Appendix, have two main features, a head and a shank and without
exception the tools are produced from steel bars and then turned/milled and heat-treated after which
carbide inserts are added to give the finished product. The carbide inserts may be of rectangular section,
which are brazed into position, or they may be small and cylindrical, which are inserted into circular holes
and retained by the interference fit between hole and carbide. Where rectangular type inserts are used only
two or four per tool are fitted, but where the cylindrical type are used the number may vary from 10 on a 50-
mm diameter tool to 120 on a 200-mm diameter tool. This latter type of bit accounts for 70 per cent of
production and is called a button bit whilst the other is called a cross bit and is a more traditional design.
The product range, whilst limited in its geometric variations Is very large with some 1,000 catalogue items
to which must be added a wide variety of specials to suit particular needs. The grade of carbide, number
and pattern of buttons, design of flushing hole, etc. are all varied to enable the tool to perform better in
varying geological conditions. Thus, in reality the product range consists of 2,000 to 3,000 items.
The variations are:
• Shank types:
o Splined: 4 types; Head diameter range 115-200 mm
o Threaded: 6 types; Head diameter range 46-100 mm
• Head diameters: Range 38-200 mm; Number of diameters 42
• Carbide grades: 4 ;
• Steel types: 1
THE MANUFACTURING PROCESS
The process is predominantly a flow batch process. The vast majority of the product range, tools, follow
virtually identical routes (see Appendix). Set-up time accounts for approximately 26 per cent of capacity of
the machines. Keeping set-ups to a minimum is currently achieved by both grouping identical product
orders together to form larger batch sizes and using the current set-up on any machine as a sequencing
guide, that is do all the jobs that require the same setting first and then change the setting.
MANUFACTURING FACILITIES
Murray recently purchased most of the machines from Barstrom's old plant in Bristol. The transfer of the
machines took three months. Some machines are still not in their final positions, and a number are still
giving problems – one grinding machine has never run properly. This resulted in a substantial increase in
the number of employees, the number of machines to be operated, the volume of the material to be
processed and the complexity of the whole operation. The layout of the machines is consistent with the
stages of the manufacturing process. Infrastructure, such as industrial engineers, maintenance, plant
engineers, accounts, etc. is shared with other parts of the group.
MANUFACTURING STRATEGY
Murray believes that their competitive advantage in tool-bit manufacturing lies in the price at which they
can provide a wide range of tool-bit products. Their strategy is to use economies of ·scale to achieve lower
costs. To this end, they have created a small plant within plant to produce low volume items (less than ten
off), allowing the main plant to concentrate on the higher volume orders. Hard state operations, however,
were all grouped together.
BARSTROM AGREEMENT
Barstrom used to have their own production facility in Bristol but closed it in favour of a sole supplier
agreement with Murray for a substantial discount on list price. The agreement on order quantities is that
the minimum order quantity should be thirty units, unless annual demand is less than thirty, in which case
the minimum quantity is twelve units. Approximately 40 per cent of orders are for the minimum quantity of
twelve. However, there are many instances where a series of orders for twelve off have been placed in
consecutive months for the same product. Therefore, there is room for improvement at Barstrom. Orders
are processed on a make-to- order basis and usually go into stock at Barstrom.
QUICK TOOLS LTD
Although part of Murray Group, Quick Tools Ltd is run as a separate company. Order intake at Quick Tools
is handled separately and delivery dates are quoted by Quick Tools salesmen without reference to Murray
where the parts are manufactured.
The standard lead time for Quick Tools orders is only eight weeks, because work pack drawings and route
cards are put together by Quick Tools and are ready for loading at Murray.
INVESTIGATION OF LEAD TIME
The Managing Director
'Our biggest problem here is the amount of time spent setting up.' complained Sid Beckett, the new MD of
Murray. 'Our average batch size is only thirty bodies. If only we could reduce the set-up times and introduce
cellular manufacturing, the released capacity could be used to shift all this inventory faster and bring our
lead times down.' Commenting on the high level of WIP, Beckett stated that the latest report suggested
around 10,000 bodies and added, 'We've not been reaching our output targets recently. We were aiming for
1,000bodies per week but only seem to be managing around 700. You should have seen the WIP inventory
earlier in the year, we were up to our waists in the stuff!' Asked if sales had been bit by the recession yet,
Beckett commented that Murray sales this month were down on the previous months, but it was difficult
to say whether or not this was due to the recession. Commenting on the twelve weeks quoted lead time,
Beckett informed: 'Some jobs are still here after four or five months but, usually, they are non- urgent jobs.
We can push a job through in just over a week when we have to. But, in general, most jobs are going through
in twelve weeks, two to three weeks in the office and nine to ten weeks on the shop floor.' 'We use a
standard costing system, so we do not really know what each item costs because we do not have a
standard set-up time. Standards are only calculated for run times. We are having our costing system looked
at by our accountant$. They are due to report in a couple of months. 'Lost time can be determined from the
operators' time sheets. Scrap and rework are recorded each day in the Inspection logbook. Inspection also
log the work going to and from subcontractors and into stores.
The Production and Materials Controller
The WIP report produced on the computer system was out of date and not regarded as reliable by any of
the staff, including Fred Pearse, the Production and Materials Controller (PMC): 'Many of the entries for
batches of one and two units are items which have been scrapped but not yet taken off the system. Also,
some of the items on the list have been dispatched but the records have not worked their way through the
system yet.' Overall, the computer report overestimates WIP by about 10 %.
The report was produced weekly and comprised a list of part numbers with quantities sorted by due date
and then by location. For example:
Due Date Location Part No. Description Quantity
Week 17 Off Soft State 972364222 150 DTH Spline 2
It was normally only printed out for due dates which had already passed. It was, therefore, being produced
to monitor arrears rather than to monitor material flow through the plant. Maintaining delivery performance
proved to be a difficult task, which required a special exercise to be carried out. When asked about a record
of lost time, Pearse replied that the Senior Foreman kept the operator time sheets and that they would
contain that sort of data but that he did not monitor lost time: 'The Industrial Engineers occasionally
monitor it. As for scrap and rework, that is monitored. Speak to Phil Johnson, the Production Manager, he
has the figures.
The Production Manager
On receipt of order enquiries from Barstrom, Kenhandt or Quick Tools, a 'due date' would be issued in line
with capacity and the order entered into a register by due date. Over a period of three to four weeks, the
register would be checked for orders of identical part numbers and, where found, a single larger batch
created. This would then be issued to the shop floor.
'lt would probably take about forty-eight hours to machine an average tool, if you include set-ups, but that
would be for an average batch, which is around thirty bodies,' commented Phil Johnson, the Production
Manager. Asked about capacity calculations, Johnson said: 'From our dispatch figures, it would appear that
our capacity is around 800bodies per week at present. Prior to the Barstrom deal, we were making around
700 per week. We should be capable of reaching 1,000 per week but some of the foremen aren't pulling
their weight and some of the new machines aren't capable of producing what Barstrom said they would.
“We've had a lot of trouble with the machines we bought from Barstrom. They have been breaking down a
lot and we have been unable to reach the output levels we expected. Also, we are short of setter operators,
so some of the younger lads have to wait for a setter operator before they can proceed with their set-up. A
·few months ago, we also had a problem with a shortage of inspectors, but we have solved this by reducing
the amount of inspection required. During the early months of the year, when we were installing the new
machines, we had higher than usual scrap and rework levels, but this is now under control”.
Capacity Calculation
It was possible to analyse the output history of both of the main sections of the plant (Soft State and Hard
State). The Inspection Logbook logged jobs out of Soft State to heat treatment and shotblast, and they were
also logged out of Hard State to Inspection and then to Stores. The average through-put for Hard State, that
is logged to Stores, was around 700 bodies per week – less than the figure of 800 quoted by Phil Johnson.
At no point had output reached 1,000 bodies per week. Appendix 3 was prepared to show the machine
hours needed for an average batch size of twenty-six in soft machining and an average batch size of twenty-
three in hard machining. These were based on an analysis of the route cards of the most common products,
covering 80 per cent of the previous eight months' output and some supporting data.
The average batch size in Hard State is lower, due to the inclusion of the small batches from the low volume
plant.
Shop floor scheduling
Shop floor scheduling was carried out by looking first at the set-up of a particular machine and then at the
requirements of the various jobs in the queue. If there was a job with similar set-up requirements close to
the front of the queue, it would be pulled forward. If not, the next job in sequence was loaded and the
machine re-set. The due dates on the route card were often no help to the foremen, since they had often
expired. In the foremen's office was a large board with 'T'-cards slotted into it for each batch going through
the plant. These cards were inserted under the particular machine heading at the top of the board and had
the dispatch date for the batch marked on the card.
The foremen had no information on what works orders were going to be released next and only the 'T'-card
board information on which jobs were waiting upstream of Hard State. The sequence of work the foremen
had given to the machine operators was frequently changed by instructions given by the MD and Production
Manager. These instructions were usually issued in response to calls from customers trying to expedite
overdue orders.
Asked about the lack of Information, the foremen agreed the system was chaotic, but what could they do?
The Hard State Foreman mentioned that previously they used a report which listed the complete WIP
inventory. by plant section, subcontracted activities, etc. but had stopped using it because it was so
unreliable, and anyway priorities were always being altered. So now they just planned from day to day using
due dates as a basis and tried to reduce the number of set-ups where they could.
Sales discipline
Sales were received in two ways. First, Barstrom would send an order to the Production Manager each
week. He would allocate a date by which the work could be completed. ln theory, this was based on a
twelve-week lead time plus or minus a few weeks, depending on the quantity of tool-holders due for delivery
at that time. The same approach was used for Kerhandt orders. Second, Quick Tools would top up the
Barstrom orders if they could or raise an additional order for those products not ordered by Barstrom. Quick
Tools were supposed to be supplying their customers from stock, but this was often not possible because
of shortages. Thus, many of the Quick Tools orders were required by customers as soon as possible. lf a
competitive delivery time could not be given, the customer would often phone around for a faster delivery
This prompted the salesmen to quote unrealistic delivery dates in the hope that Production would rush
them through: 'Oh, but we can't turn down £6,000s' worth of business because they wanted delivery in four
weeks. I know that is less than the normal lead time, but if we push it through, we can make the due date.
Anyway, we can't afford to refuse important customers. If we don't have the stock, we have to rush it
through.' Phil Johnson often accepted this situation, and this resulted in orders going through with due
dates that were impossible to achieve or had even passed.
An analysis of orders received against bodies logged to stores (the nearest measurement available to
orders dispatched) showed that there was virtually no correlation between the two, even allowing for a
twelve-week or longer lead time. By physically counting the WIP on the shop floor and extrapolating the
order input/output data back to the beginning of the year, historical WIP inventory and order backlog could
be plotted (see figure below). (Due to the lack of any records of works order releases to the shopfloor, Soft
State WlP inventory cannot be separated from the order backlog.)
Lead time
With a measure of capacity and WIP Inventory, it was now possible to make an estimate of manufacturing
lead time. By making a rough assumption that the through-put of 800 bodies per week was the same for
each machining stage in Soft State and 700 per week for each Hard State stage, the lead time broke down
to roughly four weeks' administrative lead time (office processing and hatching up) plus nine weeks'
manufacturing lead time. Eighty per cent of the manufacturing lead time was due to queueing and 75 per
cent of the administrative lead time due to the practice of delaying works order releases in the hope of
creating larger batches.
Final assembly
Another area where lead time was increased was in final assembly. Finished bodies were often delayed
due to the lack of carbide inserts and packaging materials. The system employed was for the PMC to order
the bought-in parts when ordering· the raw material for the bodies and to place works orders for any in-
house components at the same time as placing the works order for the bodies themselves. Often the
quantities were small and therefore the placement of the orders would be delayed to increase the order
size – and occasionally forgotten or lost. The same often applied to in-house· works orders.
The information system
Information was gathered and passed on by several individuals: the Managing Director, the Production
Manager, the PMC and the Senior Foreman. All did so separately, on hand-written sheets of paper which
they used at progress meetings. The PMC used computer system reports, but system data were not kept
up to date. No one had definitive information and even when the Managing Director passed photocopies of
his sheets round, no sooner where they Issued than they were changed. In effect, Murray had no single
systematic method of processing the information necessary to run the factory effectively.
Figure 2: BareStrom Late Deliveries Distribution
Figure 3: Alternative shank styles for rock drills
Table 3: set-up times, run times, manning levels and machine hours
Notes: Table 3 uses the available data for set-up times, run times, manning levels and machine hours,
available to calculate the machine loading factors at each stage of the process. The average through-put
of the Hard State is around 700 bodies/week, significantly lower than the 1,000 bodies/week the company
would like to achieve. Weighted average run times were averaged from product route cards weighted in
accordance with the volumes produced of each product over the previous eight months. A day or night
shift is thirty-nine hours per week. Overtime amounted to four hours per week.
Figure 4: Manufacturing Process flow for Button and Taper Socket rock drills
Assumptions and considerations for Modelling of the Murray System
Please read the following assumptions before you attempt to model the process of this case
study.
Main Assumptions:
1. Simulation is to consider only the "Splined type" and the "Threaded type" drills;
2. There are only a total of 4 milling machines and 4 turning machines. The quantity of other
machines is to be reasonably selected based on this.
3. For the original model, the lot sizes of both soft state and hard state are 26. The current output
as per the company data is around 700 bodies/ week but Murray would like to raise the output to
1000/week with minimal cost.
4. The original setting follows a functional (process) layout as it is a batch process. Similar
machines are positioned together as a centre (such as a milling centre). Same machine types
will only be split if similar consecutive operations must be done by the same type of machine.
For example, the turning machines could be split into two adjacent stations of 2 lathes each to
accommodate the consecutive ''Turn" operations at the beginning of the process.
5. You can add buffers of capacity up to 7 between stations, as appropriate.
Note: where there are cyclic flows of parts (returning parts) remember to give priority to the more
advanced parts. This helps to avoid clogging.
The first step on this project would be to produce a diagram with a functional layout showing the
flow of parts clearly.
**Engineeringmanagementsystems.docx**
This file is too large to display. [View in new window](https://www.sweetstudy.com/files/engineeringmanagementsystems-docx)