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The purpose of this paper is to evaluate design performance of 51 gear shaping machines by using data envelopment analysis (DEA).

Existing studies extend traditional DEA by handling bounded and discrete data based on envelopment models. However, value judgment is usually neglected and fail to be incorporated in these envelopment models. In many cases, there is a need for prior preferences. Using existing DEA approaches as a backdrop, the current paper presents a methodology for incorporating assurance region (AR) restrictions into DEA with bounded and discrete data, i.e. the assurance region bounded discrete (AR-BD) DEA model. Then, the AR-BD DEA model is combined with a context-dependent DEA to obtain an efficiency stratification.

The authors examine different AR restrictions and calculate efficiency scores of five scenarios of AR restrictions by using the proposed AR-BD DEA model. It shows that AR restrictions have a great impact on the efficiency scores. The authors also identify nine efficient frontiers in total. For each decision-making unit, it could set benchmarks and improve its performance based on each higher efficient frontier.

This paper first evaluates efficiency of gear shaping machines by considering different (bounded and discrete) variable types of data and including AR restrictions. The AR-BD DEA model and context-dependent AR-BD DEA model proposed in this paper further enrich the DEA theory. The findings in this paper certainly provide useful information for both producers and consumers to make smart decisions.

THE SHAPING MACHINE THE mechanically operated shaping machine can be used during the earlier years of the course to demonstrate setting‐up, tool angles, cutting angular faces, and adjustment of stroke and feed.

FORMED in 1927 by a group of engineers and first established in a small works in Staines, Middlesex, the business of the company had grown so much within eight years that more extensive premises were required. Accordingly, a factory was built at Staines which helped to meet the large demand for gear cutting machines and tools for military equipment that came with the Second World War. Prior to the War and as soon as possible afterwards, W E Sykes developed a considerable export trade as well as an increasing home market and by 1951, a large expansion was required. The original small premises became the Sykes Machine Tool Co, a leading importer of tools and equipment from Europe and the USA. The export trade of the main company was facilitated by the formation of subsidiaries in Canada and Australia and by the appointment of numerous established firms as agents.

Manufacturing manager, Alan Jackson and senior production engineer, Peter Allen talk to Jack Hollingum about Lewmar Marine's major investment in robot‐automated cell manufacture.

IN arranging a machine shop for the manufacture of acro‐engines, great care has to be taken in the arrangement to ensure that the layout is open without wasting space, at the same time making the most economical use of the floor space available. Also the lighting should be carefully arranged so that the operators can satisfactorily produce their work to the required degree of accuracy, which is necessary in aero‐engine production.

IT was in February that we condemned the Finniston Report on the grounds that it had failed to tackle what was surely the first consideration: the definition of what an engineer is. Out of the dozens of recognised qualifications and the countless unqualified people who can and do call themselves engineers, albeit of one sort or another, it is surely impossible to set up one colossal Authority to control the lot, without that definition.

In medium and small scale series production the aim of the automatic charging of the machines is affected by frequent tool changing. Conventional charging and interlink systems do not offer the sufficient changeability to achieve a profitable and productive application. For this purpose, Industrial Robots do offer a lot more possibilities. The high purchase costs, however, here too, do very often not permit an economic use. The aim of the development outlined in this paper was therefore to charge several machines on which different pieces being deposited in different stores are machined, by means of a centrally located robot. The sequence programme for this robot being extensive and the times for machining the pieces being varying a fixed charging order cannot be realized. As the robot control must select certain subprogrammes based on defined criteria a computer has been incorporated as the core of the control. In virtue of this technique the defined decisions can be taken and the tool changing can take place individually without disturbing the operation of the remaining machines.

The Minister of Civil Aviation, Lord Pakenham, has appointed Mr J. Roland Adams, K.C., to hold a Public Court of Inquiry into the accident which occurred at Mill Hill, London, N.W.7, on Tuesday, October 17, 1950, to the British European Airways Dakota aircraft G‐AG1W.

A tool geometry, unique to Karl Hertel Ltd., of Nuneaton, is enabling British Aerospace to maintain continuous production of thin‐walled missile motor bodies. The workpiece material is a “difficult” extruded 4% copper‐aluminium alloy.