An exact solution technique for M/M/s multi-server demanding queue is introduced, and a general form of the curves representing service rates of the system is presented. As the number of customers in the system increases, the service rate is shown to increase initially, then decrease, and finally converge to a certain value. It is also shown that this phenomenon persists regardless of the numbers of servers and customer types.

By the mid 1960's the rate of productivity growth in the manufacturing industries of the United States reached the lowest level ever recorded in the American economy. As a result the cost-offsetting operations that had been a century-long part of cost minimizing became less feasible. U.S. manufacturing firins apparently embarked on a pattern of a cost pass-along management. Accounting for price variation as a function of a shift from cost minimizing to cost pass-along is the main subject of this investigation. An econometric model of the inflation process is presented which indicates a clear shift in the modal behavior of manufacturing industries from cost minimizing (1948-1964) to cost pass-along (1965-1975). The latter behavior, initially triggered by the drag of resource diversion on the productivity growth process, undermines the pressure toward productive efficiency that is at the core of industrial engineering, and at the center of U.S. industry's ability to remain competitive.

The performance of scientific researchers has been studied from a number of different aspects, mostly in developed countries. This paper attempted to identify salient factors influencing scientific performance at individual level in a developing country. A model describing the productivity and performance of scientific researchers was developed. Four hypotheses were derived from the model; i) the degree of diversity of a researcher will affect the degree of his scientific performance, ii) the degree of dedication will affect the degree of his performance, iii) the degree of research pressure will affect the degree of his performance, and iv) the degree of satisfaction will affect the degree of his performance. Data were collected through questionnaires responded by 48 researchers from two research organizations. The results of data analysis supported the hypotheses in part. Specifically, diversity measured by the number of research areas was related to the productivity of research reports (p<0.05); research pressure influenced the average number of research papers (p<0.05). The results of hypothesis testing of the satisfaction showed mixed directions according to the indicators. Even though the results of data analysis did not support the hypotheses unanimously, probably due to the limitation of sample size, most of the descriptive analysis indicated that the direction of hypotheses in developed countries seemed to be similar in developing country too. However, more research efforts are needed to verify the research findings of developed countries in developing countries.

When the number of stockable item types is too large in certain large scale inventory operations, it is important to classify and screen out the items that need not be stocked; and for the low demand or high cost items, it may be preferable to use one-for-one-ordering policy. In this paper, the problem is formulated in somewhat easier terms, and a criterion is developed that can be used in deciding what items not to stock.

This paper presents the validation of a stochastic model of muscle fatigue during static muscle contractions. Forty four laboratory experiments, covering eleven test conditions for two trained subjects, were run in order to estimate fatigue and recovery rates, based on EMG observations. The validation of the model was made by comparing the model predictions to the experimental fatigue time. The validation study supports that the stochastic model of muscle fatigue accurately represents the underlying fatigue process. The study also provides support that the fatigue model can be used as a monitor of individual muscle capabilities.

조립 라인의 평형 정도와 생산성 향상 가능성을 분석하기 위해 MTM 기법이 적용되었다. 포니 자동차의 변속기 조립 라인의 실제 사례 연구를 통해 가장 많은 작업량이 있는 애로 공정이 MTM 자료에 기준하여 127% 효율로 작업되고 보통공정이 102% 효율로 작업되는 것이 조사되었다. 이는 이 라인의 능률이 양호하다는 것을 보여 주고 같은 수의 작업자로 두배까지의 생산량 증가라는 현 관리자의 희망대로 될 수 없다는 것을 보여 준다. 더욱 많은 생산량을 원한다면 더 많은 작업자를 투입해야 할 것이고 만약 작다면 더 적은 작업자로 더 많고 균형된 작업량을 할당하는 것이 필요할 것이다. MTM 분석중 여러가지 방법 개선점이 지적되었고 이는 작업 사이클당 육체적 노력을 증가시키지 않은 상태에서 표준 시간의 감소와 작업량의 증가를 의미하는 것이다.