An Investigation into some Problems of Finished Vehicle Body Shell Production at Pressed Steel Fisher Ltd

Abstract

This thesis deals with some of the major problems involved
in painting and trimming motor vehicles at a particular production
unit of British Leyland.

These problems were identified as :-
(a) the procurement of sufficient quantities of component
parts to fulfil a demand.
(b) the allocation of the available stock to meet some
objective when the supply of parts is interrupted.
(c) the sequencing ‘and control of the painting and
assembly functions.

On the question of material procurement it was found that
there was a remarkable lack of communication, on a sufficiently
detailed level, between the sales organisation and the satellite
production units. Vehicles were scheduled by the Sales Organisation
for which there was insufficient stock and there were
vehicles unscheduled, for which stock was available, and therefore
could have been produced.

Two stages of a solution are suggested. Firstly to form
a feed forward information loop in terms of a formal communication
link between sales and the provisioning organisations in order that
future demand patterns can be detected and material provisioned
accordingly. The next stage is to use a linear programming
model to test various purchasing and order scheduling strategies
prior to fixing a firm demand.

The second problem area involved allocating the stock on
hand, which due to extraneous factors may well not be of the ideal level, to meet some management objective.

The problem was beyond manual solution and the technique
of mathematical programming was used to determine optimum
solutions. The problem was strictly an integer programming
one but a technique was developed constraining a normal linear
approach to give acceptable results without the unpredictability
found with a pure integer technique. The solution produced an
‘optimum build program and illustrated strategies which could lead
to an improvement in the objective.

The third and final problem area investigated involved
studying the reactions of the production system with the aid of
a computerised simulation model. The model was found to be an
accurate representation of the actual system and sensitivity
testing indicated changes in strategy which would result in an
improvement in production efficiency. These points were
developed further and a strategy is submitted which will result
in an improvement in the efficiency of the production system.

Date of Award	1971
Original language	English