Engineering Costs and Production Economics最新文献

The phenomenon of developmental polarization, that is uneven regional development, strongly affects the production cost in the periphery of a country. This, in turn, seriously affects a peripheral enterprise's competitive posture and ability to survive. The increased transportation cost, the lack of friendly industrial environment and sufficient infrastructure, the manpower problem and the need for a centrally located branch of the enterprise are included among the most unfavorable factors for the production cost in Greek peripheral production units. An assessment of the production cost in such a unit showed an 18% increase due to these factors. Measures to counteract regional unevenness include development incentives and creation of industrial estates. Nevertheless, such measures, unless they address the increased production cost problem in the long run, can only marginally improve the regional distribution of productive activities. The paper discusses the relation between production cost and location, analyzes the factors affecting the production cost in the periphery, describes the support given to peripheral enterprises in Greece and suggests policies which would relate this support to the operating cost of such enterprises.

This paper introduces a conceptual cash flow model for strategic capital investments. The model focuses on the dynamic situation in the business environment and investments as tools for the management during the whole lifespan. The main purpose of the model is to understand the economic consequences of an investment, although it is impossible to express them all in figures when making the decision. As the conceptual model needs no figures, this problem is avoided.

The cash flow for the base investments is separated into two levels, basic cash flow and total cash flow. The net present value of basic cash flow can be calculated and may be negative although the investment is profitable. The calculation of total cash flow requires knowledge which is not available when the decision is made.

The concepts of options and pre-options constitute the difference between basic and total cash flow. They are used to focus the opportunities which are created by the investment but not taken into consideration in basic cash flow. These considerations have to be taken otherwise, but all of them cannot be translated into money.

This paper opens with a discussion of the need for a Computer-Integrated Manufacturing (CIM) strategy, and the relationship of CIM to an organisation's general use of information technology. A brief review of a number of equipment selection methodologies is then presented, and their applicability assessed. A methodology for equipment selection for CIM developed by the authors is described. This is illustrated by the case of Company A, who applied the methodology when selecting a computer-aided design (CAD) system, and a local area network. Amongst the main findings, it is shown that equipment selection must be driven by strategy, not technology. Whilst the technical issues are complex, the ‘political’ and organisational issues may have a strong influence. Integration must be considered early on in the equipment selection process, if CIM is to be implemented successfully.

This paper considers a T period planning problem for single stage in which a sequence of known demands D₁,…, D_T must be satisfied. An efficient calculation reducing theorem based on cost-path and a new recurrence relation is developed to find optimal policies. Several regeneration points can easily be obtained by comparing setup cost to holding cost. We also prove that the knots of a cost-path satisfy the necessary conditions of the Wagner-Whitin algorithm. The new concept could also be used to eliminate the number of additions in the optimal lot size problem for multi-stage assembly systems.

Manpower planning models rarely incorporate effects of learning on production capacity. Here those effects are explored through some models. First, we discuss a discrete-time model in which capacity is maintained at a desired level through appropriate recruitment and layoffs. Then we propose a related continuous-time partial differential equation model, and derive the recruitment rate level which will maintain capacity. Some examples are provided.

This paper discusses the impact of judgmental modelling on resource allocation and strategic decision making in R&D departments of a chemical industry. It outlines the development of a decision support system to facilitate research planning and management control and describes its use over a period of time. This is followed by an examination of the emulation and adaptation of the approach by a newly formed subsidiary of the company and its conducive and stabilising effects on the concomitant organisational changes.

This paper presents an approach to study multi-item inventory systems operating under several simultaneous resource constraints employing the Non-linear Goal Programming (NLGP) technique. A solution procedure based on the ‘complex method’ is employed which eliminates the drawbacks in the existing algorithms. Multiple and conflicting goals can be considered in the approach proposed whereas in the existing approaches to inventory systems under resource constraints this was not possible. Four types of cases are considered to illustrate the approach. Results have been compared with existing approaches wherever available. In other situations modelled; the results look intuitively satisfying. It is envisaged that interactive software based on this technique may help support decision making effectively in a multi-criteria situation.