摘要:

Contextual variables, such as an organization's attitude toward an innovation and the innovation's compatibility with existing operating practices and value systems within the organization, may moderate the relationship between the need for strategic change, and the decision to implement an innovation and the ability to realize the benefits of success from the innovation. In attempting to investigate this relationship within the context of a special category of innovations for the manufacturing process—computer-integrated manufacturing (CIM) systems—this large-scale empirical study finds fairly strong support for the moderating effects of both these variables on the form of relationship within the organizational innovation process. Adopting organizations already holding, or capable of generating, a favourable attitude toward CIM display a much stronger association between their need or pressures for strategic change and the extent to which they are able to exploit the performance potential of these innovations than do adopting units having a less favourable attitude. A somewhat counterintuitive finding (on the face of it) is the negative moderating influences of compatibility of CIM. The results suggest that incompatible CIM innovations appear to facilitate a stronger linkage within the stages of the innovation process, raising questions about the rationality involved in adoption and implementation of these CIM innovations.

ISSN:0020-7543    

DOI:10.1080/00207549408957066

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A common problem of cellular manufacturing systems is the formation of part families and machine cells. The total number of inter- and intracellular movements have to be minimized because both contribute to lower productivity. Nevertheless, we show here that intracellular movements are not so important compared with the intercellular movements. We give an efficient algorithm based on minimizing the total intercellular movements, pointing out the importance of being very careful in the selection of the key workstation of each cell. The algorithm has been tested with problems selected from the literature. The results show that in all cases we get a higher utilization rate and lower central processing unit times that other algorithms published in the past.

ISSN:0020-7543    

DOI:10.1080/00207549408957067

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Economic design of control charts seeks to choose the parameters of control charts that will minimize the cost. In an economic model, the time to the occurence of an assignable cause is usually assumed to follow an exponential distribution. In addition to this assumption, certain approximations are used in the optimization procedures. This paper extends the current economic design for X¯ charts in two directions. First, economic design is considered for a general distribution for the time to the occurrence of an assignable cause. The method is specialized to several distributions such as Weibull, lognormal, folded-normal, folded-logistic, and gamma. Second, an exact method to obtain the optimal design parameters is developed. Using Duncan's examples, the optimal designs obtained by exact method are compared for different distributions. These are also compared with the approximate optimal designs given by Duncan. This comparison shows that the optimality of the design for X¯ charts is insensitive to the distributional assumption of the time to the occurrence of an assignable cause for small values of the sampling interval.

ISSN:0020-7543    

DOI:10.1080/00207549408957068

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The modelling and analysis of Flexible Manufacturing Systems (FMS) has been approached through a variety of methodologies, which diverge considerably in their ability to represent and analyse complex FMS features. This paper broadly classifies the chief approaches, and evaluates them against certain prescriptions. Petri Nets and their extensions score highly on the evaluation criteria. A modelling approach is presented based on Conditional Predicate/Transition Nets (CPrTN), which extend the modelling power of Predicate/Transition Nets. CPrTN provide formal, concise and graphical models, eminently suited for modelling the often complex dynamic interactions in an FMS.

ISSN:0020-7543    

DOI:10.1080/00207549408957069

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A generalized transportation model is first formulated for the scheduling of Surface Mount Technology (SMT) production. Its dual form is next discussed. By specially coding the SMT scheduling problem, it is unnecessary to develop the constraint matrix for the dual. The simplex method is not applicable for this problem due to its sparse data structure. An efficient algorithm for the dual model is then developed from the idea of the revised simplex method. To illustrate the algorithm, a numeric example is presented.

ISSN:0020-7543    

DOI:10.1080/00207549408957070

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A modified analytical model of the NC-tool path for face milling of flat convex surfaces is developed. The staircase milling for the path parallel to the specified edges of a polygon is considered. Differing from the former approach, the influence of the location of the starting point, the supplement of a path for the uncuts parts, and the end reduction are permeated in this paper. Using the modified model, the object can be machined completely and the total length of tool path will be reduced.

ISSN:0020-7543    

DOI:10.1080/00207549408957071

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

We present a new computerized shop generator designed for research related to cell formation. The generator can take advantage of the following input data: number of parts and machine types in the population, part-machine matrix density, part and machine categories and proportions of parts and machines belonging to each category (the part categories classify parts depending on the number of machine types that appear in their routeings; similarly, the machine categories classify machines depending on the fraction of the part population they process), probabilities to determine machine sequence patterns (including possible revisit-ations), part demand, unit processing times, productive capacity per machine type, and maximum allowable utilization per machine. As part of the output, the shop generator creates randomized part-machine matrices. It can also calculate the required number of machines of each type and their utilizations, and produce machine sequences with and without backtracks. A unique feature of the generator is that it does not create part-machine data by reshuffling matrices with known block structures (i.e. the solution to the cell formation problem is unknown). Rather, data characteristics of the shop(s) to be cellularized are entered into the generator as input parameters. These parameters can be either hypothetical or based on typical characteristics found in industrial manufacturing data bases. The shop generator software, programmed in Turbo Pascal, and a user's manual are available from the second author.

ISSN:0020-7543    

DOI:10.1080/00207549408957072

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Production scheduling models that determine part mix ratios and detailed schedules do not usually account for deadlocks that can be caused by part flow. Deadlocks must be prevented for operational control (especially in automated systems). The major thrust of this paper is in developing a structured model for deadlock detection, avoidance and resolution caused by part flow in manufacturing systems. A system status graph can be constructed for the parts currently in the system. Deadlock detection amounts to determining deadlocks in the system status graph. On the other hand, deadlock avoidance amounts to restricting parts movement so that deadlocks are completely avoided in the future. While deadlock detection is a one-step look ahead procedure, deadlock avoidance is a complete look ahead procedure. Deadlock resolution or recovery amounts to judiciously using a limited queue to recover from deadlocks. Deadlock detection and avoidance are absolutely crucial to uninterrupted operation of automated manufacturing systems. A model based in graph theory has been formulated to detect and avoid deadlocks in automated manufacturing systems.

ISSN:0020-7543    

DOI:10.1080/00207549408957073

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

We discuss the factors influencing palletization. A heuristic has been developed to cope with the three-dimensional palletization problem in which boxes have different base dimensions and can be grouped by same height. The layered-pallet-loading technique has been applied to the proposed heuristic. Brown's Linear Equation Approach has been modified and incorporated in the proposed heuristic to determine the optimal layout for each layer. Then a stability analysis is conducted to determine the optimum layer order and layout. The application of the proposed heuristic is illustrated by an example.

ISSN:0020-7543    

DOI:10.1080/00207549408957074

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper analyses and evaluates six of the promising cell formation techniques by comparing and contrasting them in relation to the scores of efficiency indices of the exceptional elements and inner-cell densities, work-load balance, and under-utilizations in different scenarios. Accordingly, all six are more or less altered with proper extensions to realize a broader capability. Effectiveness of the suggested efficiency measures in the evaluation is also illustrated. Each technique seems to have a favourite operating area of its own considering a variety of factors.

ISSN:0020-7543    

DOI:10.1080/00207549408957075

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor