摘要:

In this paper a new approach to the construction of the functional block diagram (FBD) and function evaluation system is proposed. It makes it possible to apply to design-stage value engineering (VE) and/or production-stage VE. The main aim is to describe and illustrate a formal procedure for the graphic presentation of the FBD and the evaluation of function items, given the necessary information concerning the relation of each function item to each other function item. Through application of this method the target cost for each part and/or each function can be derived. In order to show how the proposed method works, a practical example is illustrated.

ISSN:0020-7543    

DOI:10.1080/00207548508904733

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

It is important for every organization to identify and develop a performance criteria system which is the basis for effective management planning and control. An integral part of every evaluation system deals with decisions concerned with the choice of criteria to be evaluated, establishing standards for those criteria, and the desired measurement frequency. The paper discusses the issues mentioned above with an emphasis on operational performance criteria such as time per unit and percent of defects. Research results concerning the evaluation of three different techniques for assigning relative importance of performance criteria are presented. Results show superiority of one technique over the other two. Methodological issues and implementation examples taken from service organizations are presented and discussed.

ISSN:0020-7543    

DOI:10.1080/00207548508904734

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Hole production using deep drilling techniques is a rapidly expanding area of manufacture but the mechanics of the process is little understood. This paper attempts to shed some light on the role of the burnishing pads in the process using a quick stop device. Conclusions are drawn regarding the generation of the hole surface integrity and its relationship to the mechanics of the process. A specific burnishing pressure is introduced which allows estimates of the pressures and energies associated with the burnishing action to be made. The experimental work shows that the hole quality is dependant upon the performance of the burnishing pads as is the economics of the process which is affected in a way which had not been previously recognized

ISSN:0020-7543    

DOI:10.1080/00207548508904735

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

This paper presents the measurement and a statistical analysis of the resultant force system, consisting of an axial force and torque, inBTAdeep hole machining. The measurements were performed using a specially designed two-component piezoelectric dynamometer and adopting the rotating cutting tool-stationary workpiece procedure. The dynamometer was calibrated for static and dynamic outputs and techniques were employed for increasing the measuring accuracy and reducing the cross-interference by obtaining the elements of the system transfer function. Experiments were carried out to measure the mean values and the dynamic fluctuations of the axial force and torque. The recorded data was processed and analysed to establish all major statistical properties of the axial force and torque. Results show that the dynamic fluctuations of the axial force and torque inBTAdeep hole machining can be represented by a stationary wideband process with a gaussian density distribution function. Such a mathematical model is essential for evaluating the dynamic response of the machine-workpiece system as well as the true motion of the cutting tool tip, and to establish the reliability of the machining process.

ISSN:0020-7543    

DOI:10.1080/00207548508904736

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

We refer to the process of uncovering the causes of failure in service of a manufactured item as ‘industrial diagnostic’. Based on our experience with such a problem over the past two years, we concluded that traditional approaches are inadequate, while the more modern approaches of ‘system failure diagnosis’ are tailored more towards the detection of failure in a complex piece of equipment than towards the detection of failure over the ‘life cycle’ of a product.

ISSN:0020-7543    

DOI:10.1080/00207548508904737

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

In recent years, many flexible manufacturing systems have been or are being developed. FMS is important in order to adapt to severe changes in market and technology and also to increase productivity. In this paper, the evaluation variables of flexibility are proposed and factors improving the flexibility of single-stage production systems with different characters are discussed. However, most production systems are multi-stage mixed type systems. This paper also points out the characteristics of the amplification of multi-stage production systems as one of the important factors affecting the flexibility and productivity of the systems. Furthermore, some ways of reducing the amplification by the ordering systems are also presented. The multi-stage ordering models discussed here are simplified, neglecting the characteristics of the single production systems which make up total multi-stage production systems and neglecting parameters concerning transportation and material flows. The flexible manufacturing system of today is treated as a stage which is part of an overall system consisting of a succession of production stages with difference characteristics. However, it should also be considered as a way to increase the flexibility and productivity of the system as a whole.

ISSN:0020-7543    

DOI:10.1080/00207548508904738

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A scheduling/rescheduling procedure is proposed for real-time control of a computerized manufacturing facility managed by a central manufacturing operating system. The procedure implies schedule revisions upon significant operational changes such as machine breakdowns. Experiments to evaluate the total production time of a computerized manufacturing system with breakdowns under scheduling/rescheduling have yielded advantages of between 25% to 7-0% compared to fixed sequencing and priority despatching procedures, respectively. Computation times required for the scheduling procedures on a CDC 65OO/66OO have also been studied. The scheduling/rescheduling procedure for an actual facility required less than two minutes, and the computation time can be regulated by the selection of parameters in an approximate method of scheduling.

ISSN:0020-7543    

DOI:10.1080/00207548508904739

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The effects of inflation and the time value of money on the optimal policies of the order-level system and the economic lot-size system are examined. Two different inflation rates, one for the internal and the other for the external costs, are assumed. The objective is to minimize the present value of the total costs per unit time.

ISSN:0020-7543    

DOI:10.1080/00207548508904740

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A theoretical investigation into the mechanics of ultrasonic machining is presented in this paper on the following lines: the material removal in ultrasonic machining is due to the periodic hammering by the cutting tool on the workpiece material through rigid spherical abrasive particles. The dislodging of material from the workpiece during machining is due to brittle fracture. No consideration is given to the cavitation erosion and the removal of the material due to the impinging of the flying abrasive particles which are being projected onto the workpiece material by the vibrating tool. Simulating by the principle of elastic waves propagation, the strain energy density distribution in a brittle half space, when a single rigid abrasive grit gives a single ‘half-wave displacement with a cutoff’ to it, is ascertained. The fracture profile due to this is found and the material removal rate is calculated. Maintaining the same amplitude of vibration, the static loads at the abrasive workpiece contacts are calculated, for different sizes of abrasive grits, independently. Finally, the variation of machining rates for constant static loads with the mean diameter of abrasive grains is determined, for the given amplitude and frequency of vibration. The results agree with the experimental observations available in the published literature (Nishimura et al. 1959)

ISSN:0020-7543    

DOI:10.1080/00207548508904741

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

In a recent issue of this journal, Mitraet al.(1983) introduced a new heuristic LTC2 for lot size planning under time-varying demand. LTC2 is based on the least-total-cost (LTC) method, which tries to balance set-up costs against holding costs. LTC2 can be interpreted as applying the Silver-Meal (1973) heuristic in the first two periods of a procurement cycle only, and applying a certain LTC version in all other cases. This paper argues that the Silver-Meal heuristic usually performs better than the conventional LTC versions and that, on average nothing can be gained by combining the LTC and Silver-Meal procedures. In this sense, LTC2 is only a first step in the right direction: away from an inefficient LTC procedure.

ISSN:0020-7543    

DOI:10.1080/00207548508904742

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor