Some of the steel works and machine tool manufacturers representing the whole spectrum of these industries in Korea are surveyed with a viewpoint from total quality control. The operation of quality control system in these fields has been found to be unsatisfactory partly because these industries are relatively young compared with those in advanced foreign countries, and partly because there have been insufficient financial and top management support. Some suggestions are made for the improvement of steel and machine tools quality. One of them is introducing the industrial engineering techniques, with additional quality control costs and full management support, into the company-wide quality control system.

The physical distribution system is composed of all the activities associated with getting products from the factory to the consumer through the firm's channels of distribution. An increasing amount of attention has been recently devoted to the component problems associated with distribution system analysis. This paper analyzes effect of system parameters which are safety factor of depot's stock, limitation of direct supply from shop stock to customer and ordering quantity on the physical distribution cost and the evaluated items by the Simulation. The distribution system simulator views system as being composed of three structural entities, presents a case study of a Chemical manufactures and carried on one year computer running.

We consider the problem of determining the optimal replacement policy of the items which deteriorate appreciably with time and become obsolete. Most of the conventional engineering economy models including the widely-accepted MAPI model assume linearity of technological improvement over time, in obtaining the economic lives of items and the net present values of the replacement alternatives under consideration. The main achievement of this paper is in that it successfully relaxes this strict linearity assumption to accommodate various other types of technological improvements in determining those values. Based on these results, we also include in this paper the mathematical models by which to determine the optimal replacement policies of items both under and without capital budgeting constraints.

The trend of computerization is significant in Korea even at its beginning stage, especially for governmental administration. However, full-fledged success of computerization in an organization is reported to be rare while the cost of computerization has been high and increasing. This paper is concerned with two features for the successful implementation of a computerized system in an organization selection criteria for the computerization among the possible candidate projects and project selection models. Due to the dearth of literature regarding successful implementation of computerization, other sources of literature with respect to R & D management, method engineering, etc. were reviewed to develop a set of factors influencing successful computerization. Thus, project selection criteria for computerization of governmental administration are developed and organized as follows: cost of computerization project including both system development and operating cost, quanitative and qualitative benefits of computerization project, probability of technical and implementation success of computerization and other organizational and political factors to be considered. These criteria are broken down into detailed sets of subcriteria to be measured. To select a project after thorough consideration of the selection criteria, a project selection model which takes into account all criteria together has to be developed. In the study three project selection models are suggested and developed. They are the checklist model, multi-stage cut-off model, and composite criteria model. A detailed procedure for each of the three models is illustrated. Although the project selection criteria and models are developed here primarily for the computerization of governmental administration, they are easily applicable to other settings of computerization. Finally, some caveats for the use of selection criteria and models are discussed.

Mission effectiveness, which is the probability of successfully completing the assigned mission, is introduced as an appropriate measure of effectiveness for a military system. The model of mission effectiveness is developed for a system which is required to carry out various types of a mission. Each mission type is characterized by the maximum allowable time that determines the success of a given mission type. A given type of a mission is successful if and only if (i) the system is available at the start of a mission and (ii) the system completes its mission within the maximum allowable duration of time that this given mission type specifies without any failure during this period. Both analytic and simulation approaches are employed. Difficulties involved in the anayticl approach are discussed. The model is proposed as a useful tool for consistent system evaluation and optimum test design.

This paper investigates the reliability characteristics of a system consisting of a unit operating on-line and backed by n spares among which m units are kept "warm" as standbys ready to go on-line. The on-line unit has an arbitrary lifetime distribution, while the warm standbys have exponential failure time distributions. The Failed units are repaired and brought back to service. The cold spares do not fail while in storage. Solution of this extremely complicated queuing problem using a "renewal counting" approach is presented and extended to the situation where the warming-up takes non-negligible time. Finally, an approach to the economic system management is discussed, considering the long-run availability, cost of keeping spares and repair facility, and the associated cost of restarting the system, after a system failure. The model presented in this paper will have many applications including the determination of the spares inventory and the number of field spares to be "carried".

PERT/CPM type scheduling systems use a network to graphically portray the interrelationship among the activities of a project. This network representation of the project schedule shows all the precedence relationship regarding the order in which tasks must be performed. In this paper an algorithm is presented that changes the network configurations without violating precedence relationship of the original network.

A double sampling procedure with zero acceptance number for the first sample whose operating characteristic closely matches that of a given single sampling plan and whose combined sample size does not exceed that of the given single sampling plan is proposed. The proposed double sampling plans corresponding to the MIL-STD-105D plans are tabulated and it is found that their ASN's are considerably smaller than those of corresponding MIL-STD-105D single or double sampling plans.