摘要:

Multi-level lot sizing problems are difficult to solve optimally when the product structure contains more than a few items. This paper identifies conditions on the cost parameters which, when applicable, allow items to be combined for purpose of optimization, thereby reducing the size of the problem.

ISSN:0020-7543    

DOI:10.1080/00207548708919877

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Several imperfect inspection operations are available in a discrete production environment. A decision regarding acceptance or rejection of the produced items needs to be made without exceeding specified limits for the probabilities of accepted units being non-conforming and rejected units conforming to quality specifications. A branch and bound approach is used to find the inspection sequence resulting in least expected total inspection cost. Following the heuristic construction of a trial solution, a dominance relationship is applied to search the tree of possible sequences for the optimal sequence. A numerical example is included.

ISSN:0020-7543    

DOI:10.1080/00207548708919878

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The existing economic analyses of metal cutting processes enable the machining conditions to be identified which correspond to such things as minimum cost or maximum production rate. The work presented in this paperextends a previously published analysis for the deep hole drilling process where wear occurs at both cutting edge and pads. The minimum cost analysis showed that the interaction between the cutting edge and burnishing pads wear resulted in a cost-feed-speed surface exhibiting a number of marked steps, an effect not present in conventional single point analyses. This extension of the analysis involves investigation into the effects of the strategy adopted for the final regrinding of the drill where cost penalties may be incurred under certain circumstances. Also included in the analysis is the effect of using disposable drills.

ISSN:0020-7543    

DOI:10.1080/00207548708919879

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper deals with the development of an algorithm for concurrent formation of part-families and machine-cells in group technology. The acronym ZODTAC stands for zero-one data: ideal seed algorithm for clustering. The present algorithm is an expanded and improved version of the earlier ideal seed method. The formation of part-families and machine-cells has been treated as a problem of block diagonalization of the zero-one matrix. Different methods of choosing seeds have been developed and tested. A new concept called ‘relative efficiency’ has been developed and used as a stopping rule for the iterations. The ZODIAC procedure and its theory are given in detail. Test results with a 40 × 100 matrix are shown.

ISSN:0020-7543    

DOI:10.1080/00207548708919880

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper considers a highly automated manufacturing line which consists of a sequence of workstations. Relatively small buffers are assigned between workstations in order to guarantee a small manufacturing interval and quick feedback in the event of process failure to make acceptable product. These small buffers could lead to a noticeable loss of line capacity due to the phenomenon of blocking and starvation. We show by means of simple examples how the buffer sizes and the mix and loading sequence of different types of jobs could significantly affect the production rate of the line. A linear programming based method is then developed to estimate the line capacity for a given configuration of machines and buffers sizes and for a given job mix and sequence. This method also gives the expected machine utilizations, the time machines are blocked/starved and, more importantly, the reason for this lost production capacity. By judiciously interpreting this information, one or more of the following steps can be taken to improve the production rate: (a) change the loading sequence, (b) increase the buffer space selectively, (c) make the products in smaller or larger batches, and (d) add new machines.

ISSN:0020-7543    

DOI:10.1080/00207548708919881

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A multicriteria quality control model for acceptance sampling is developed which defines several conflicting and non-commensurate objectives. The following objectives are proposed and quantified in this model: (1) to minimize the cost of inspection, (2) to minimize the number of critical defects, (3) to minimize the number of major defects, and (4) to minimize the number of minor defects. The interactive paired comparison method identifies the most desirable sample sizes and acceptance levels for critical, major, and minor defects for a given lot size. At each iteration a small number of alternatives is presented to a decision maker. The decision maker chooses the most favourable alternative by expressing his/her strength of preference for pairs of alternatives. An unknown non-linear utility function of objectives is assumed. The optimal sampling plan is determined using a minimal number of interactions.

ISSN:0020-7543    

DOI:10.1080/00207548708919882

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The flow of material during injection upsetting was studied to identify areas of the process which would require either, detailed definition or the use of simplifying assumptions, to enable the development of a complete mathematical model. Equipment for injecting El CM aluminium on to an upsetting platen and into a die-cavity, and a plane-strain equipment for injecting slabs of plasticene, were used to examine the characteristics of sliding in the injection chamber, of flow at the exit and of flow into the die-cavity. Considerations which are critical to the modelling of injection upsetting are the friction losses within the injection chamber, the presence of regimes of flow behaviour which are bounded by specific values of flange thickness and the identification of the extent of the transitional flow prior to the establishment of a steady-state distribution of shear surfaces. The accommodation of the strain-dependent behaviour of materials requires a fundamental description of strain within the upset flange.

ISSN:0020-7543    

DOI:10.1080/00207548708919883

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The problem of on-line production control for a robotic manufacturing cell producing parts of different types is analysed. The approach described in this paper expands the results of an earlier study so as to provide for sequence-dependent (deterministic or exponential) processing times at the cell. In addition, a novel production control strategy permitting temporary suspension of the cell's activities at certain decision epochs is formulated. Several numerical examples are given to illustrate the productive potential of this formulation. They seem to indicate the superiority of the new strategy presented here to earlier optimal control strategies in which the cell had to be active as long as it was unblocked.

ISSN:0020-7543    

DOI:10.1080/00207548708919884

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper deals with the problem of developing a production ordering system which maintains high reliability and productivity of multi-stage production and inventory systems with capacity-constraint and machine breakdown. In this paper, two ‘push type’ production ordering systems (Matsuura and Soshiroda 1981) are proposed according to information feedback methods. The influence of forecasting error, the difference between forecasted demands, down-time, and the backlog caused by the restriction of production capacity, upon the production and inventory levels is analysed by each production ordering system. The results indicate that, in designing an effective production ordering system, a feedback method must be chosen according to the conditions of the average loading ratio, the down-time, and the autocorrelation coefficient of demand.

ISSN:0020-7543    

DOI:10.1080/00207548708919885

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0020-7543    

DOI:10.1080/00207548708919886

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor