Optimum Allocation of Inspection Eﬀort in Multistage Manufacturing Processes Research Day 20 June 2008 Ali Gassim Shetwan, Mechanics Group School of Engineering firstname.lastname@example.org Durham University Overview The research aim is to optimise the allocation of quality inspection stations to critical manufacturing operations. It takes into account the constraints on inspection resources, in terms of funds and labour, and aims to minimise the waste in production. The aim will be achieved by combining discrete event simulation with optimisation and failure analysis. Relevance The quality policies in many companies evolve continuously over a number of years by focusing on quality issues that are critical at any given instant of time. This is approach that does not take into account the need for global analysis of the quality problems and does not use the available resources in an optimal way. As a result of that many companies experience signiﬁcant losses from unﬁnished or defective products. In the present economic climate, the production of waste becomes of paramount importance because it aﬀects the overall competitiveness of the manufactured products. A literature review on the topic has shown the importance of the problem. Lindsay and Bishop  presented a method for determining minimum cost allocations of screening inspection eﬀort to assure both a quality requirement and a linear cost of outgoing defectives. Unreliable serial production systems with known failure probabilities at each station are studied by Penn and Raviv . The dynamic programming, and a branch and bond are used to solve the problem of determining an optimal quality control station conﬁguration. Furthermore, Shiau  applied a genetic algorithm with a realistic unit cost model to solve the manufacturing resource allocation problem by concurrently performing process planning and inspection planning. Research Method To achieve the aim the following objectives have been formulated: 1. To develop simulation models used for Monte-Carlo simulation of diﬀerent manufacturing processes,that produce low volume high technology (LVHT) products. In order to experiment diﬀerent what-if sce- nario related to quality policies. Derive a generic model representing this class of processes. 2. Using the generic model, develop appropriate optimisation techniques for allocation of limited funds to strategic quality improvement alternatives in order to maximise the quality and reduce the waste. 3. Develop reliability analysis models to investigate the possible reasons for failures occurring in LVHT processes. 4. Develop method for implementing the reliability information in the quality optimisation process. References 1 Lindsay, G F and Bishop, A B. Allocation of Screening Inspection Eﬀort - A Dynamic Programming Approach Management Science, 10(2): 342–352, 1964. 2 Penn, M and Raviv, T. Optimising the Quality Control Station Conﬁguration, Naval Research Lo- gistics, 54: 301–314, 2007. 3 Shiau, Y R, Lin, M H and Chung, W C. Concurrent Process Inspection Planning for a Customized Manufacturing System Based on Genetic Algorithm, International Journal Advanced Manufacturing Technology, 33: 746–755, 2007.