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Develops and describes a knowledge‐based systems approach which maybe used to highlight the disparity between the essential and/ordesirable prerequisites for the…
Develops and describes a knowledge‐based systems approach which may be used to highlight the disparity between the essential and/or desirable prerequisites for the implementation of effective master production scheduling (MPS) systems and what actually exists in a given manufacturing environment. Identifies seven high level MPS implementation issues: level of understanding of MPS systems; procedures and responsibilities for MPS creation; planning horizons, time‐buckets and time fences; capacity feasibility of the MPS; dealing with backlogs; adherence to the MPS; and what to master schedule. Asks questions to determine the presence or absence of necessary prerequisites. If a high level prerequisite, relating to procedures and data, is not present, further lower level questions are asked to assess the reasons for its lack, and how it may be provided. This gap analysis approach makes it possible to identify in advance the major problems which must be addressed to ensure the effective implementation of master production scheduling systems.
Previous research has not addressed the problem of developing a masterproduction schedule (MPS) for production systems with minimum batch‐sizeproduction restrictions…
Previous research has not addressed the problem of developing a master production schedule (MPS) for production systems with minimum batch‐size production restrictions. Proposes a weighted integer goal‐programming model for the development of a rolling horizon master production schedule, under conditions of demand certainty, for a process industry environment with multiple production lines and minimum batch‐size production restrictions. The presence of multiple and often conflicting goals prevalent in production planning and scheduling is explicitly incorporated in the model. The model can easily be implemented on a microcomputer and the master production schedule developed is in spreadsheet format and can easily be understood by a practitioner. Uses a case study conducted for a paint company to illustrate and validate the model. Results show that the MPS developed using the proposed model is superior in terms of total cost when compared with actual company performance.
Concentrates on two key aspects of manufacturing resource planning(MRPII) theory and design, namely; how master production scheduling iscarried out in differing business…
Concentrates on two key aspects of manufacturing resource planning (MRPII) theory and design, namely; how master production scheduling is carried out in differing business environments and how well the “closing of the loop” operates by checking the capacity requirements of the different levels of plans within an organization. The methodology involved detailed investigations into master scheduling and capacity planning in eight diverse manufacturing companies. This was followed by a nationwide survey of users, a survey of all the major suppliers of production management software in the UK and an analysis of the facilities offered by current software packages. The main conclusion which is drawn is that in the majority of companies, only just over 50 per cent are attempting resource and capacity planning and only 20 per cent are successfully feeding back capacity requirements planning (CRP) information to “close the loop”. Various causative factors are put forward and remedies are suggested.
Reports a new method for preparing a product structure analysis toimprove the effectiveness of the master scheduling function for productsthat are manufactured on an…
Reports a new method for preparing a product structure analysis to improve the effectiveness of the master scheduling function for products that are manufactured on an assemble‐to‐order basis. This methodology for conducting product structure analysis uses relational database management software to identify common and unique material in a product structure. Highlights example results of the application of methodology.
A hybrid flowshop (HFS) problem on the pre‐sewing operations and a master production scheduling (MPS) problem of apparel manufacture are solved by a proposed two‐tier…
A hybrid flowshop (HFS) problem on the pre‐sewing o perations and a master production scheduling (MPS) problem of apparel manufacture are solved by a proposed two‐tier scheduling model. The first objective of this paper is to plan a MPS for the factory so that the costs are minimized when the production orders are completed before and after the delivery dates required by the customers. The second objective is to minimize the completion time of the pre‐sewing operations in the cutting department while the production quantities required by the sewing department at several predetermined times can be fulfilled by the cutting department. Experimentation is conducted and the results show the excellent performance of the proposed scheduling model for the apparel industry.
MRP is a priority‐planning technique, not an execution tool. Wastecan be avoided through the use of JIT as an execution tool, where onlythose materials which are actually…
MRP is a priority‐planning technique, not an execution tool. Waste can be avoided through the use of JIT as an execution tool, where only those materials which are actually needed on the factory floor are “pulled”, when they are needed. Describes a hybrid manufacturing system which incorporates the traditional MRP system and the Japanese JIT system in a single framework. The rationale is not whether MRP or JIT is better; it is how they complement each other in a hybrid system. Specifically, this framework attempts to integrate both MRP and JIT production. The integrated hybrid system can provide better production planning, scheduling and control. It employs the logic of MRP and JIT, but it eliminates some of the inherent problems and drawbacks in both systems.
Two distinct models of delivery reliability versus delivery speedare tested. On the basis of data from a survey of 193 manufacturingfirms, factors associated with the…
Two distinct models of delivery reliability versus delivery speed are tested. On the basis of data from a survey of 193 manufacturing firms, factors associated with the “planning” systems of firms, such as production‐plan goals achieved, inventory goals achieved, and master schedule performance, were found to have a significant effect on delivery reliability. In follow‐up interviews with 13 plant managers; it was found that “process”‐related factors were associated with delivery speed capabilities. Specifically, the biggest inroads to be made into delivery speed are first on the design/manufacturing interface, secondly on the subsequent “translation” of these designs to supplier requirements, and lastly on the production floor in terms of process layout.
When sales vary significantly according to season, the manufacturermakes special provisions to integrate the acquisition of raw materialsand labour with an effective…
When sales vary significantly according to season, the manufacturer makes special provisions to integrate the acquisition of raw materials and labour with an effective production schedule which satisfies customers′ requirements. The recommended procedure is called aggregate planning, and many algorithms produce a good definitive solution. However, they have been ignored by industry. The empirical research presented here looks at such planning in a sample of 20 Australian factories. It sheds some light on the acknowledged gap between theory and practice, and suggests that business strategy, the extent of the seasonal distortion, and the tactical remedies available, are all linked. Strategic and tactical considerations tend to bypass the aggregate planning step, and the problem is ultimately resolved at the master production schedule level.
Schedule instability is a major problem in companies using materialrequirements planning (MRP) systems. The effectivenesss of using bufferstock to combat nervousness in…
Schedule instability is a major problem in companies using material requirements planning (MRP) systems. The effectivenesss of using buffer stock to combat nervousness in the master production schedule (MPS) of an MRP system is investigated. An example scenario illustrates the need for caution in using buffer stock for reducing schedule instability. Detailed simulation results are presented which suggest the need for further research to understand the role of buffer stock in achieving stable master production schedules.
This monograph will review recent thinking as applied to the management of materials within organisations. In considering the type of organisation to which the comments will apply, it is of use to recognise the following sectors: