Case study of Process Planning.doc

7/24/2019 Case study of Process Planning.doc

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Case study1: Manufacturing at McCall Diesel Works

Introduction

McCall Diesel Motor manufactures a range of diesel engines for use in marine applications,

manufacturing plants and agricultural applications. The company has always tried to be progressive

in terms of product design and in fact pioneered the development of a particular type of internal

combustion engine. Originally, they only manufactured large marine diesel engines but have now

diversified into small stationary type engines.

Design

Many of the engines designed were one-off products and made specifically to order. Although this

type of wor still represents !" per cent of those manufactured, there has been a move towards

standardi#ing many of the component parts to reduce the variety of parts. This allows a degree of

interchangeability, especially for small components such as mechanical fasteners. There also has

been reduction in the variety of engine si#es available with the introduction of a standard range of

three engine si#es$ %", &" and !"'(.

Production planning

)n terms of production planning and control, there is no formal system in place. )n fact, there is

resistance from the (roduction Manager to implementing any such formal system. The lac of any

such formal system has resulted in high *)( and failure to meet delivery times due to lac of *)(

monitoring and information on manufacturing lead times. (roduction planning has also failed to tae

advantage of the economies of scale afforded by the use of standard parts. They issue orders for

small lots of the same part up to eight times in a month. There is also lac of a formal approach to lot

si#ing and how the lots are processed through the shop floor. This has led to lots being lost and the

order being reissued only for the lot to turn up.

Manufacturing

)n eeping with the approach to production planning and control, there is no formal recording of any

manufacturing data. This has resulted in there being no operations lists for any parts as it is left to the

discretion of the individuals involved. The tas of routing parts through departments and se+uencing

the operations is left to the manufacturing department foreman. The manner in which he carries this


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out has resulted in high set-up costs and thus, high manufacturing costs in general. Despite all of the

above, the manufacturing methods employed are sound and reliable and appropriate for the type of

manufacturing system being employed. Most of the e+uipment is general purpose in nature, although

pieces of e+uipment are close to obsolescence. )t is intended that this will be replaced with

dedicated, single purpose production e+uipment. Although there is a facility for the design and

manufacture of special tooling, there is very little use made of this. inally, there is poor utili#ation

of the production e+uipment available and this often leads to bottlenecs occurring, despite the fact

that there is sufficient capacity on the shop floor.

Summary

The senior management recogni#es that in order to survive, there is an urgent need for change.

'owever, they are having difficulty in convincing the worforce of this and implementing any

change. )n the main, the management sees the problem as the resistance of the worforce to change

their woring practices. 'owever, the worforce see the main problem as being the fact that the

senior management are essentially sales minded and dont understand the problems of production

planning and manufacturing.

Discussion points

. *hat ind of manufacturing environment have McCall Diesel *ors traditionally employed/

Comment on the type of worforce, plant layout and e+uipment.

%. 'ow is the manufacturing environment changing based on the increased use of standard parts/

0. Comment on the state of the design1manufacture interface.

&. 2ased on the type of manufacturing environment, what sort of process planning documentation

would you e3pect to see in a company lie this/ *hat level of detail would you e3pect to see in such

documentation/ 4ist typical data you would e3pect to see.

5. *hat role do the industrial and +uality engineering functions play in the company with regards to

process planning/

!. 'ow does this companys approach fit the model of production planning and control presented in

the chapter/


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Case study 2: Planning at High Performance Pumps6

Introduction

'igh (erformance (umps is a small, successful manufacturing organi#ation that speciali#es in

manufacturing a range of pumps. This success is due to the performance, +uality and reliability of

the product and the e3cellent bac-up service. The pumps range in si#e from 785mm to large

70""mm pumps. The smaller pumps are manufactured in batches of "" and the large specials in

batches of five. 'owever, regardless of si#e, all pumps use the same manufacturing processes.

Manufacturing processes and planning

There is a ma9or common component for all pumps and this is a camshaft. The si#e of the camshaft

varies according to the si#e of the pump. The process sills involved in the camshaft manufacture are

highly developed and considered cost-effective compared with competitors. )n fact, one of the areas

of e3pansion is the design and manufacture of camshafts for other companies for their products, with

camshaft production increasing by &"" per cent in the last ! years. :early all of this increase was for

customi#ed products in a wide range of volumes. 'owever, regardless of the production volume, all

camshafts are produced according to the same process plan and machine routing.

Design and manufacture

Although business had significantly increased over the last ! years, there are some significant

problems within manufacturing. The most noticeable of these is the high *)(, which has tripled

during the ! years. 'owever, there was another ma9or problem with regards toproduct costs. (roduct

design had initiated a value analysis programme to reduce the cost of standard products by " per

cent. This initiative resulted in a number of design changes.

Manufacturing blamed the introduction of design modifications, in con9unction with the overall

increase in product variety and drop in volume, for the problems. 'owever, product design refusedto accept any of the blame for the poor performance of manufacturing and suggested that the

problem was with the poor manufacturing planning and control system.

There are further problems with the method of product costing. There is a lac of detailed

information on component costs and process costs, therefore, due to the use of common processes

across the various product ranges, a ;blanet overhead rate is used. This meant that the customi#ed


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products were costed using standard cost data. inally, the cycle times and lead times being used

were very often inaccurate.An e3ample of this is that the planners are using lead-times of

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Case study of Process Planning.doc