Operation scheduling with GT and PBC

Generations of managers in industry and of academics in universities, have been intrigued by the problem of how to plan, and more recently how to automate the scheduling of the operations needed to make parts, on the machines and other work centres in a factory. Today, with one possible exception (OPT) (Goldratt 1980), we are no nearer a reliable solution than we were 100 years ago. Early attempts at centralized operation scheduling, were based on Gantt charts or planning boards. Later solutions have used the computer. They all face the problems that with traditional forms of organization, there is a very large number of constraints which affect the solution, and that if a machine-breakdown, absent worker, material shortage or other disaster makes it necessary to change the schedule, it is generally impossible to revise it to suit the new situation quickly enough to keep the factory running. The usual solution is: ‘Tell the foreman to do the best he can’. This paper submits that the introduction of group technology (GT), coupled with period batch control (PBC), so simplifies the problem, that with minor analytical assistance the GT group foremen can do their own operation scheduling, more reliably and cheaply than it can be done by the computer.     

A FUZZY ALGORITHMIC APPROACH TO THE CONSTRUCTION OF COMPOSITE INDICES: AN APPLICATION TO A FUNCTIONAL LIMITATION INDEX

This paper presents a fuzzy algorithmic approach to the construction of composite indices. The method uses a fuzzy analytic translation of a linguistic definition of the composite index, where the definition involves more primary concepts for which scales already exist. An application to the construction of a functional limitation index is presented. Comparisons between the fuzzy algorithmic approach and a more standard, tabular approach are also shown. The results suggest that the fuzzy algorithmic approach yields essentially the same index with less effort and some conceptual advantages.     

The Conversion of a Boron-Containing Pyrotechnic Mix to a “Ceramic-Like” Material by Electron Beam Interaction

The transformation of a boron-containing pyrotechnic mix to a “ceramic” vitreous-like material by the impingement of an electron beam on a boron-barium chromate pyrotechnic, in a scanning electron microscope, is reported. The thickness of the “ceramic”-like material is ×250 the penetration depth for the electron beam and indicates that a self-sustaining chemical reaction was induced by interaction of the energetic material with the electron beam at temperatures well below the mix's ignition temperature of over 1000?°C. This links with earlier observations on the low-temperature liquefaction of boron to boron suboxides in an electron microscope.     

Effect of Frozen Storage on the Gel-forming Properties of Hoki (Macruronus novaezelandiae)

The possibility of using frozen hoki to make surimi was investigated. At intervals, fish were thawed under controlled conditions and gels were then made from minces of the flesh. Both puncture and torsion tests showed the quality of gels declined with duration of storage of frozen hoki. This decline was matched by a decrease in pH and an increase in formaldehyde concentration in the frozen flesh. The data suggest a land-based surimi plant could not be operated outside the harvesting season to any appreciable extent using frozen hoki stored at -29°C.     

Optimization of Blanching for Crispness of Banana Chips Using Response Surface Methodology

Whole green bananas were blanched in water at 50, 60, 70, 80, 90, and 100°C for 2, 15, and 30 min using a factorial design then peeled, sliced and fried in oil to make chips. Crispness was measured using a bending-snapping test in the TA.XT2 Texture Analyzer. Significant interactions were found between blanch time and temperature and crispness of chips. A second experiment was then performed using a central composite design and blanch temperatures from 41.7 to 98.3°C. Response surface analysis predicted that crispiest chips should be produced at blanching conditions of 69°C and 22 min.     

Thermal Expansion and Chemical Durability of Phosphate Glasses

The thermal expansion coefficient and aqueous dissolution rate were measured for alkali phosphate glasses containing a third and fourth component. For a given series, both properties increased monotonically as the radii of the alkali ions increased. The observed expansion coefficients were in the range 99 to 286 × 10⁻⁷°C⁻¹. A small mixed-alkali effect was observed for both properties.