The optimal operation planning of a Kanban system with variable lead times

In the majority of the previous research on Kanban systems delivery lead time is treated as a fixed value. In many practical situations, however, the lead time is variable. In this paper, optimal operation planning of a fixed interval withdrawal Kanban with variable lead times is proposed. A cost is incurred for inventory level less than the safety inventory level, since the risk of shortage of inventory must be considered. Behaviour of the optimal number of Kanbans and the withdrawal interval of Kanbans are investigated in terms of various parameters such as standard deviation and mean lead time.     

Shop floor characteristics influencing the use of advanced planning and scheduling systems

The purpose of this article is to investigate how the manufacturing process, the shop type and the data quality, i.e. the shop floor characteristics, influence the use of advanced planning and scheduling (APS) systems in production activity and control (PAC). The methodology implemented is a multiple case study at three case companies. Each company has different shop floor characteristics, but all use a scheduling module in an APS system, which supports production scheduling. A theoretical framework is developed suggesting how APS system are used in the PAC activities, and which major aspect to consider. The case analysis shows that the scheduling module in APS system, foremost supports sequencing and dispatching. In particular, the shop type is influenced by the decision of how often the APS runs and what freedom is given to the shop floor. The manufacturing process influences how the dispatch list is created. Contrary to the literature presuming that APS systems are most suitable in job shop processes, it is found that the manufacturing process is not a crucial factor when deciding whether APS systems are an appropriate investment. It is found that the level of data quality needed in the APS system depends to a large extent on how the dispatch list is used. For example, is the dispatch list used as a guideline, not a regulation, the need for accurate data in the module is reduced. This article extends the previous literature concerning APS systems by analysing how APS systems influence PAC as a whole and increase the understanding of the challenges of using APS systems in PAC.     

A decision-based approach: application to the automatic design of process planning

The notion of centre of decision presented in this article defines a conceptual and generic model enabling us to represent and use expert knowledge. It is suitable when the problem to be solved can be broken down into a sum of interdependent subproblems. Actions can be planned progressively and previous decisions can he modified by a backtrack mechanism. This principle is iterative. The structure is made up of many independent rules and an action plan. The customization of the application is possible even if the software evolves with future updates. This model has been applied in the LURPA-TOUR software which is a computer-aided process planning system for rotational parts.     

Note: A note on the production and inventory systems taking account of time value

This paper deals with the optimal inventory decisions taking account of time value by applying the concept of the present value method, and modifies the bounds for the optimal cycle time described in Chung et al. (Production Planning & Control, 1998, 9, 580–584). A modified algorithm to compute the optimal cycle time is developed to improve the paper of Chung et al. Finally, a numerical example is given to illustrate the algorithm discussed in this paper.     

A simulation analysis of the impact of family configuration on virtual cellular manufacturing

Past research has shown that it is possible to simultaneously achieve the setup efficiencies of traditional cellular manufacturing systems and the routeing flexibility of a job shop by viewing cells not as permanent, physical structures, but as temporary, 'virtual' entities. This research demonstrates that the advantages of virtual manufacturing cells can be obtained over a range of part family configurations. In particular, virtual cellular manufacturing is robust to changes in the number and size of families being processed. Further, the research shows that the benefits can be obtained under setup conditions impartial to a family-oriented part environment.     

A contingency view on the impact of supplier development on design and conformance quality performance

This study extends contingency theory’s account of organisational size and culture by exploring the relationship between supplier development and internal quality performance. Drawing on supplier development research, the study aims to examine the moderating impact of organisational size and culture on the relationship between supplier development and design and conformance quality dimensions. Using survey data of 518 UK manufacturing organisations, we found that larger organisations with greater access to resources and a strong supply chain orientation culture tend to place the most weight on supplier development programmes which in turn yield higher internal quality performance. These findings contribute to ‘Operations Management Practice Contingency Research (OM PCR)’ and will raise awareness among operations managers of their future sourcing decisions.     

A longitudinal analysis of the impact of firm resources and industry characteristics on firm-specific profitability

Using a dynamic heterogeneous panel data model, we examine the relationship between firm-specific resources (corporate management capabilities, employee value-added and technological competence) and firm-specific profitability and the potential moderating effects of industry characteristics on this relationship. We find that firm-specific resources enhance both accounting-based measures (return on assets and return on sales) and market-based measure (Tobin’s q) of firm-specific performance. Moreover, industry characteristics moderate the relationship between firm-specific resources and firm-specific profitability. Managerial implications are discussed.