Operational planning of discrete component manufacturing lines

This thesis reports research carried out into a novel approach to the operational planning of discrete component manufacturing lines used in the automotive supply industry. The work is based on extending the functionality of the state of the art automotive component manufacturing lines known more commonly as flexible manpower lines (FMLs). This extended system is termed a multi-component flexible manpower line (MCFML) and has the capability to produce a wider range of components than a FML at lower production costs. A major requirement of MCFMLs is to offer the flexibility and responsiveness to meet often unpredictable orders that can vary in terms of part variety and volume requirements on a daily basis. Traditional production planning and control approaches do not offer the capability to support MCFMLs, therefore this research explores the use of a specially tailored operational planning system, based on a hybrid just-in-time (HyJIT) approach which relies on safety stock to cope with fluctuations in demand. The research contribution identifies and defines a HyHT operational planning framework, consisting of finite capacity production planning (FCPP) and inventory control (IC) activities. Most significantly, as part of the inventory control activities, five stock management rules (SMRs) have been developed that determine the provision of safety stock to support production and minimise associated costs. The applicability of this novel framework has been underpinned by the design and implementation of a HyJIT software toolkit and a set of experiments that test the performance of the SMRs under various MCFML scenarios (varying in terms of order requirements and stock conditions). The HyJIT operational planning approach is shown to be an effective method to balancing MCFML resource utilisation using minimal inventory to support often volatile orders. In particular the results show that the HyJIT approach provides significant cost and time benefits over a commonly used existing stock management concept. Most importantly, this research shows that the strategic utilisation of safety stock in a just-intime (HT) environment is a feasible and effective solution to allow automotive suppliers to become more competitive and to satisfy the customised demands of today's marketplace.