Selin KÖK- 030070162- 4th week answers

1.Part Family Formation (Manufactoring Formation)

(old)

During the preparatory stage, existing components are coded, classified, and later grouped into
families (Figure 19). The part family formation can be performed in several ways. Families can be formed based on geometric shapes or process similarities. Several methods can be used to form these groupings. A simple approach would be to compare the similarity of the part’s code with other part codes. Since similar parts will have similar code characteristics, a logic that compares part of the code or the entire code can be used to determine similarity between parts.
(Gavriel Salvendy, Handbook of Industrial Engineering: Technology and Operations Management, page 476)

(new/better)

The classifications are done so that it is possible to reuse process plans for similar parts when a new part is designed. Such classification schemes therefore are based on manufactoring characteristics and can be very useful for family formation for the purposes.

The application of part family formation was fort he problem of aggregate planning. This has also been the subject of a significant research literature.

(Harvey J. Greenberg, Tutorials on emerging methodologies and applications in operations research, p.8-25)

2. Periodic Pull System  (Modelling Systems)

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Kim discusses a periodic pull system in which the manual information processing time of a kanban method was replaced by online computerized processing. This results in better system performance, such as reduced lead time and inventory and faster system response.
(Nanua Singh, Computer-Integrated Design and Manufacturing 1996, pg. 460)

(new/better)

Using the kanban system, manufactoring factories no longer needed to rely on a computer. The reasons for having employed a kanban system instead of a computerized system were as follows:

·         reduction of the cost of processing information

·         rapid and precise acquisition of facts

·         limits on surplus capacity at feeding facilities

(Andrew Kusiak, Computational Intelligance in Design and Manufactoring, p.282)

3. Tolerance Analysis  (Design)

(old)

Computer-aided approaches to tolerance analysis and synthesis fall into several different categories ( Lu et al., 1991). The earliest work focused on conventional tolerances, i.e., manipulation on dimensions, and the analyses of tolerance specifications. More recent work has focused on the issues for both the conventional tolerances and geometric tolerances, i.e., the underlying theory of geometric tolerancing, composition, and proporties such as validity and sufficiency.
(Concurrent design of products, manufacturing processes and systems, Ben Wang, p.75)

(new/better)

Tolerans analysis helps to answer what effect will the component tolerances have on circuit performance.  The most general tolerance analysis task would be predict, on the basis of the probability density functions of all components within a circuit, teh corresponding probablibity density functions of all performances of interest. In practice a more limited objective may be set, for example, to estimate the manufactoring yield.

The classification of tolerance analysis:

(Robert Spence, Randeep Singh, Tolerance Design of Electronic Circuit, p.28,29)

4. Serial Engineering (Concurrent Engineering)

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Serial Engineering is characterized by deparments supplying information to design only after a product has been designed, verified and prototyped. In serial engineering the various functions such as design, manufacturing and costumer service are seperated. The information serial engineering flows in succession from phase to phase. For example, prototype model, verified by either simulation or hardware prototyping or both is reviewed for manufacturing, quailty and service.
(Nanua Singh, Computer-Integrated Design and Manufacturing 1996, pg. 104)

(new/better)

The whole focus of concurrent engineering is on a “right-the-first-time” process, rather than on the typical “redo-until-right” process that is so common in the serial engineering mode of operation. The elimination of design iterations reduces product development costs and shortens time to market for new products.

(Jon L. Turino,)Managing concurrent engineering: buying time to market : a definitive guide, p.3

5. Prevention Cost (Accounting)

 (old)

There is an old adage that an ounce of prevention is worth a pound of cure. The prevention philosophy is essentially concerned with making the product right the first time so that the product performs well during its intended period of use. Accordingly, prevention cost include all the efforts that go into designing and manufacturing a product that meets customer requirements by preventing nonconformance. The elements of such prevention cost include activites involving quality planing and engineering, new product reviews, product and process design, process control, training and quality data acquisiton and analysis.
(Nanua Singh, Computer-Integrated Design and Manufacturing 1996, pg. 351)

(new/better)

Pollution prevention costs are made to reduce the noxious effects of wastes before they are released into the environment; they therefore prevent pollution. Pollution costs are the Money value of the damages caused by wastes after they are released into the invironment; they are therefore the costs of the pollution that occurs. It is much more difficult to identify and measure pollution costs than pollution prevention costs. We shall distinguish three categories of pollution costs.

(John Harkness Dales,Pollution, property & prices: an essay in policy-making and economics, p.13)