End user project managementfor Holset FMSby P. G. Hudson, S. WebbHolset Engineering Company Ltd.

and J. R. ChandlerThe Polytechnic, Huddersfield

A multi-process £4.5 million flexible manufacturing system tomanufacture a variety of sub-assemblies for Holset Engineering hasbeen under development for over two years. The system uses a rangeof sophisticated machines, seven gantry type robots, an AGVtransport system and numerous computer controls. Holset has takenthe unique approach of conducting the project management itself,specifying its exact requirements to equipment suppliers. This paperdiscusses the reasons for end users considering this approach, thedisadvantages in not accepting project responsibility, and the lessonslearned by the Holset FMS project team from developing a user-oriented system.

Introduction

Many references have been made to theimportance of UK manufacturing indus-try and the effect that the apparent mal-aise has upon the whole economy.Concern has been expressed regardingthe UK's deteriorating position in inter-national markets and its lack of com-petitiveness. Many different ideas as tohow the UK can stimulate new life intoindustry have been debated.

In order to achieve a recovery it isclear that, after many pleas to central

Government, Whitehall, the City, thebanks and institutions for assistance,we ourselves, the people in industrytoday, must accept the responsibilityfor creating a new attitude to manufac-turing development and the introduc-tion of new technologies [1].

The main objective for most manufac-turing companies is to manufactureproducts that customers want whenthey are wanted at the right price andquality. In the ever increasingly com-petitive international markets of today,to do this successfully requires the

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Fig. 1 Typical Holset shaft and wheel

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intelligent use of modern technologies.Most successful manufacturing com-

panies define the market requirementsin very concise terms. From this defi-nition a detailed manufacturing strategyillustrating company targets forimproved productivity, cost, deliveryand quality is produced and communi-cated to each employee. Because mar-ket trends dictate greater productdiversity, manufacturers are required toimprove their flexibility to enable themto respond to market changes and bringnew products to the marketplace asquickly as possible. This implies beingable to work with shorter lead times,smaller batches, lower inventory andstill respond to schedule changeseffectively.

There are many 'buzz' words looselydefining the new manufacturing tech-nologies, all encompassed underneaththe umbrella of computer integratedmanufacturing (CIM). One of theseimportant tools that can be used bymanufacturing companies is flexiblemanufacturing, usually referred to asflexible manufacturing systems (FMS).

There has been considerable interestin this technology for a number ofyears, but it is still not yet clearlydefined. Subsequently many possible'end users' of FMS are confused aboutits application and potential.

This is a nationally disappointing situ-ation as it is surely the end users'responsibility to strive to 'get to grips'with FMS as well as many of the othernew technologies. In fact it is essential ifthe end users are ever to drive the tech-nology suppliers to provide them withwhat it is that they really require, ratherthan accepting a compromise for thenearest best-fit on the market.

There is no doubt that in the UK mostof the potential users of FMS have takenthe easy option and gone to the con-sultancy agencies or the turnkey sup-pliers of FMS.

Computer-Aided Engineering Journal April 1986

This has several disadvantagesbesides being more expensive. Mostimportantly, it leaves the end user with-out the technological expertise thatsent him to the turnkey supplier in firstplace. It also ensures that the FMSknowledge gained during the develop-ment of the system remains with thesupplier.

This may be one of the reasonsexplaining the poor reputation held byprofessional manufacturing engineers.

From a national viewpoint this trendhas placed a disproportionate numberof educated, talented engineers in theFMS supplier sector and not where theyare especially required, within the enduser sector.

The objective of machine toolbuilders is to sell machines and materialhandling equipment. The objective ofcomputer suppliers is to sell computersand software. Of course the system sup-pliers develop and supply some tech-nically excellent systems for end users,but the learning curve experienced dur-ing development is not the end user's.

Bearing in mind that manufacturingtechnology is being developed outsidethe user areas of industry, that a largeshare of the nation's talent is not work-ing directly for the end user, is it anywonder that many potential end usersof FMS are still unsure of thetechnology?

This is surely not the way to nurture anew lean, competitive and efficientindustry.

Generally, Japanese end users haveadopted an entirely different approachto system installation. They tend tospecify their own requirements in detailfrom the company's manufacturingstrategy and, rather than compromisethemselves by asking machine toolbuilders to supply the nearest fit ofmachines, they design, build and installmany of their own [2]. The benefits arethat there is no compromise of the com-pany's manufacturing strategy, and it ishence more likely to be more suitable tothe company's plans for improved effi-ciency and productivity.

Upon completion of a new technol-ogy project, the maintenance of theinstallation is an extremely importantconsideration. It is most likely that themaintenance has to be performed bythe company's own employees. Ifinvolved in the development right fromthe start, they are then in the ideal pos-ition to carry out their work effectively.

It is the feeling of the authors that theend users within British manufacturingindustry must become more deter-mined and start the arduous task of defi-ning their own, specific requirementsmore effectively and subsequentlyimprove their own skills within the new

technologies. This must be one of thebuilding blocks upon which the indus-try's recovery can be built.

This paper discusses how HolsetEngineering, Huddersfield, identifiedits own requirements for FMS develop-ment and subsequently decided tospecify and supply its own detailedspecifications to the supplierindustries.

Company background and thecomponent

Holset is one of the world's leading tur-bocharger manufacturers, supplying tonearly every major diesel truck manu-facturer in the world.

Holset is a wholly owned subsidiaryof Cummins Engine Company and has acontinued commitment to high levels ofinvestment in order to remain competi-tive in the high-technology automotivecomponents industry.

Consistent with Holset's require-ments for continued improvement, inboth the manufacturing and technologyfields, a decision was taken to vig-orously pursue flexible manufacturing.

Subsequently, in December 1983 agrant application was submitted to theUK Department of Trade and Industry(DTI) for financial assistance with thedevelopment and installation of an FMSfor the computer-controlled batch pro-duction of the turbocharger shaft andturbine wheel sub-assembly. Everymanufacturing process required tomanufacture a shaft and wheel, fromraw material to finished part, wascovered.

The DTI accepted the proposal andpledged to finance up to 24% of the totalinvestment cost of £4.5million. Theduration of the FMS project was set at

three years, with a completion date ofMarch 1987.

The shaft and turbine wheel of a tur-bocharger is a two-piece welded sub-assembly. The 'wheel' is a high-preci-sion investment casting made fromInconel that can withstand operatingtemperatures of over 650°C. The 'shaft'is a forging from 8740 steel. The joiningof the shaft to the wheel is by welding. Atypical Holset shaft and wheel is illus-trated in Fig. 1.

During operation the assembly floatsin engine oil between twin bronze bear-ings, which are themselves fully floatingwithin the bearing housing. The journaldiameters of the shaft and wheel arecase-hardened. Again, the assembly isstress-relieved to reduce mechanicalmovement at the subsequent oper-ations and during service.

The shaft diameters are ground toclose tolerances on size, roundness andconcentricity, together with good-quality surface finishes.

The high quality level must beattained because of the high operatingspeeds experienced by the assembly,these being of the order of 120000 revo-lutions per minute.

High-performance models that oper-ate at high running speeds require thatthe shaft and wheel assembly be veryfinely balanced.

The shaft and wheel component is themost significant single element in a tur-bocharger, both in terms of cost anddifficulty to manufacture. There are atotal of 32 manufacturing processes inthe manufacture of a shaft and wheel,and consequently a good deal of hand-ling is required. There are currently fivedifferent frame sizes of turbochargerand an active demand for at least 50different shaft and wheel designs at anytime.

A x-axis servo driveB y-, z-axis servo drivesC u-, v-axis double pivot headD double-grippe^ head

Fig. 2 Gantry robot features

Computer-Aided Engineering Journal April 1986 51

Fig. 3 AGV with work pallet

Taking into consideration the manyaspects of the manufacture of a shaftand wheel it was thought that, by usingFMS as a tool, a major cost reductioncould be made along with many spin-offbenefits; most importantly the benefitof the education gained by Holset'smanufacturing and systems engineerswhile developing their own specificrequirements for the FMS.

However, it is thought that the utilisa-tion of flexible manufacturing to such acomponent as a shaft and wheel is bothunique in concept and philosophy.

The need for flexible manufacturing

As stated above, in terms of cost anddifficulty to manufacture the shaft andwheel component is the most signifi-cant single element in a turbocharger.Because the raw material cost of a tur-bine wheel casting is significantly

52

higher than that of other componentsthere is a proportionally higher level ofworking capital tied up in work in pro-gress for shaft and wheels.

Additionally, because of the relativelygreater number of machining processesinvolved in the manufacture of the shaftand wheel a good deal of floor space isoccupied by the plant dedicated to thecomponent.

Typically many companies endeavourto rationalise the large number of dif-ferent component designs that accrueover the years. There are often a largenumber of designs as a result of tryingto give the customer exactly what herequires. One of Holset's main objec-tives has always been to give the cus-tomer exactly what he requires;however, it has an obvious effect uponmanufacturing. Owing to the largenumber of different designs, smallbatches of components are inevitably

scheduled together to minimisemachine setting, which uses resourcesand is often time consuming.

Flexible manufacturing minimises theproblem of re-setting machines fromone part number to another, and con-sequently the batching together of likedesigns is no longer a problem. Indeed,with flexible manufacturing the realityof a batch quantity of one can berealised.

FMS helps to eliminate the small-batch, multiple-part-number problemand hence provides marketing with theability to give the customer exactly theitems he requires and not the best fit.

With the improved flexibility offeredby the manufacturing facility there aremany benefits made company-wide.For example, design and developmentengineers have a much greater licenceto design and release for manufactureany design that gives the optimumperformance, providing that it is con-tained within the family size envelopeof the FMS. Marketing operations con-sequently have a better quality productwith which to fight in the marketplace.Additionally and most importantly itimproves the responsiveness of thecompany to market changes.

Setting the project targets andobjectives

The nature and sequence of themachining processes required in themanufacture of the shaft and wheel dic-tate an overall workflow, from rawmaterial stores to finished parts stores,in a manner similar to that of a transferline. Alternative routings need only beconsidered when there are machinebreakdowns, preventative maintenanceis being carried out or perhaps whenthe machine is being used to produceprototypes.

As is usual with components that havea large number of processes, the shaftand wheel component has a wide vari-ety of cycle times from process to pro-cess. Hence it was considered crucial, atthe initial design stage, that a balancedworkflow for the manufacture of theshaft and wheel was required. The bal-anced line would constitute a uniqueflexible transfer line.

Certain machine processes with atotal cycle time of greater than thatrequired need parallel machiningcapability. This capability consists ofmachines of the same type, each capa-ble of producing the same variety ofcomponents.

Other machine processes have cycletimes considerably less than thatrequired. These processes are seriesoperations, each being performed oneafter the other.

Computer-Aided Engineering Journal April 1986

It is possible to allow the series pro-cesses with a cycle time of less than thatrequired by the balanced productionline to wait for the excess time betweenthe components. Alternatively the'speeds and feeds' of the machine canbe reduced to match the cycle time ofthe other machining operations. Thisaction would give the advantage ofreduced machine wear and maintainthe FMS balance, hence keeping thework in progress between cells to aminimum.

Consequently it can be seen that themachine processes with the longestcycle times effectively control the pro-duction output of the whole FMS.

When the optimum characteristics ofthe FMS project had been decidedupon, the objectives and targetsrequired to improve the flexibility of theproduction of turbocharger shaft andwheels were set as follows:

• quick changeover: five minutes peroperation• reduced batch size: batch of oneacceptable• fast response to schedule change:re-allocation of part numbers duringprocess• high throughput: 800 per day• short lead time: two days maximum• zero defects: 0% scrap• maximum up-time: 20 hours per day• uninterrupted workflow: no work-banks between operations• lower inventory: ten days maximum(includes raw material and finishedparts)• low labour costs: no direct labour• education of engineers: improvedcapability to design and develop high-technology equipment

The FMS project management

To justify flexible systems and automa-tion the traditional, quantitativemeasures of reduced labour costs,lower inventory, less scrap and rework,greater capacity, reduced energy costsand maintenance costs typically give amarginal or unsatisfactory return oninvestment (ROI).

However, if the qualitative measuresof improved on-time delivery, consist-ently high quality, faster product intro-duction, improved workflows, simplerinformation systems and improvedemployee morale and participation areconsidered then the ROI can be signifi-cantly improved.

Traditionally automation systems arejustified with forecasted increases incustomer demand. The increase in cus-tomer demand actually experienced isoften disappointing, and this reducesthe success of the total investment.Consequently, when justifying FMS, ifall feasible and realistic benefits are

considered increased demand forecastsbecome significantly less important. Itis often sufficient to consider that thecurrent demand will be maintained, andonly by introducing the FMS as a costreduction will, .the market share beincreased by more effectively compet-ing in the marketplace.

During 1983 the DTI was invitingapplications for financial assistancetowards FMS consultancies, develop-ment costs and capital expenditure.

Holset had ambitious plans toimprove the manufacture of the shaftand wheel component and the pos-sibility of a financial grant acceleratedthis interest. It was realised from anearly stage that the design of the systemwould be innovative owing to theunique characteristics of thecomponent.

After discussions with the DTIofficials during the summer of 1983 agroup of Holset production engineerswere selected to investigate the feasi-bility of developing an FMS for the shaftand wheel component. Commencing inOctober 1983, many suppliers of dif-ferent plant from welding to balancing,ovens to computer controls were askedto discuss the project.

A decision was taken not to use a con-sultancy or turnkey supplier because itwas felt that, owing to the varied rangeof machine operations, a consultancycould not possibly have the expertisethat the company's project engineershad acquired over the years.

However, it was recognised that theteams' limitations were in the areas ofcomputer control, interfacing, softwarewriting and automated material hand-ling. There was also a lack of detailedunderstanding about manufacturingterms such as manufacturing resourcesplanning, just in time, workflows, pullsystems etc. These were terms tradi-tionally used in the production controlareas but were important whendeveloping the system concept.

This knowledge, it was thought,should be acquired and fully under-stood by the project team membersthemselves rather than being hiredfrom a consultancy or turnkey supplier.

The results were favourable; it wasfound that when people were con-fronted with having to learn new skillsand hence take the responsibility forthe success of a project area theyresponded much more favourably thanif they had been mere onlookers.

The responsibility for the success ofthe project must ultimately lie with pro-ject engineers.

During the summer of 1983 Holsetentered into a Teaching CompanyScheme (TCS) with Huddersfield Poly-technic under the directorate of the DTI

and the Science and EngineeringResearch Council. The scheme wasplanned to last for three years with atotal of fourfull-time, graduate teachingcompany associates. Each associate wasoffered a fixed-term two-year contract.The first associate was selected to startwork with the project team in Decem-ber 1983 and was given the responsi-bility of working as a systems engineerwith the FMS team.

The knowledge gathered from theequipment supliers, the Polytechnicand other sources was used to producea document which was the basis for anapplication submitted to the DTI Tech-nical Committee during December1983.

The Polytechnic had a high involve-ment with the development at thisstage, and was of considerable assis-tance to the company by questioningthe proposed plans for the project, bygenerally educating team membersregarding the technical aspects thatwere met during the development andby highlighting the latest methods andtechniques being presented in the pro-duction engineering press [3]. In addi-tion, through the TCS the associates,and hence the company, had access tovast amounts of technical informationthrough the library services. It was alsofound that many of the equipment sup-pliers were an excellent source of tech-nical information.

An important aspect of a TCS is thatthe involvement of the Polytechnicteaching staff with an industrial projectmakes them more aware of industry'srequirements, and this has a beneficialeffect upon their teaching material andmethods.

During the time between the DTITechnical Committee meeting and fullgrant approval in March 1984 the projectteam consisting of the project manager,two experienced production engineersand the systems engineer from the TCSdeveloped the project plans further byinvestigating the latest manufacturingtechnologies and techniques.

Possibly the most significant dif-ference in the Holset approach to thatof other FMS users was in the approachto machine tool and automation equip-ment suppliers.

Traditionally FMS users will ask arobot supplier to interface to a numberof different machines, and con-sequently the price of the robot mustinclude interface development costs.

Holset approached the gantry robotsuppliers and instructed them that allthe robots would use exactly the samesoftware and be wired in exactly thesame way. To do this Holset had to spec-ify, in detail, the interface to themachines and a cell controller.

Computer-Aided Engineering Journal April 1986 53

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It is important to consider that some-thing of the order of 20 different typesof machines were required to be auto-matically loaded. The possibility ofusing the same control on eachmachine was remote without forcingsome suppliers to use a controlunfamiliar to them.

Consequently, the robot andmachine suppliers were instructed howthe equipment should be prepared.This ensured that when the equipmentwas connected together everything wascompatible and that every machine hadthe same interface configuration. Thisdecision ensured that Holset wouldhave the flexibility to move machinesfrom cell to cell as the order of machineprocesses changed during and after theproject development. Indeed, if in thefuture machines are required to bemoved, this does not present a majorelectrical or software problem.

Many machine cell suppliers buildsections of equipment and then dis-mantle it, transport it and re-erect theequipment together as a cell beforeshipping the total system to the enduser. It was not considered to be costeffective to do this and consequentlythe first time that the robots saw themachines was on the shopfloor atHolset.

To be confident that this was possibleHolset required the facilities to provethat the machines had been built tospecification before acceptance. Acomprehensive machine 'pass-off pro-cedure had to be planned by the engin-eers responsible for the introduction of

the respective equipment. Eachmachine was 'passed-off with the useof a robot simulator, and each robotwith the use of a machine simulator.

The site of the capital equipment wasnot known until the first machinesstarted to arrive in the summer of 1985,and consequently if it had not been forthis flexible approach to the develop-ment of the system major problemswould have been confronted during theinstallation of both the cells and thetotal system. Indeed a total plant layoutfor the project was never fixed until thefirst machines arrived. The only infor-mation that was crucial early in the pro-ject development was the total area thatwould be occupied by the FMS.

It was decided that an extremelyimportant aspect of the project was toproduce quality components. To do thisthe highest-quality machines had to beselected, without which the total sys-tem would be a failure.

After 18 months of project develop-ment the majority of the machines wereon order. At this stage more resourceswere required and a third productionengineer was recruited to take theresponsibility of finalising the auto-mated guided vehicle (AGV) and palletdesigns.

Further resources were recruited tocoincide with the arrival of the firstmachines in early 1985 and later to assistin the computer systems installation.The FMS team consisted of the projectmanager, five production engineersand two system engineers at the end of1985.

Manufacturing engineering projectwork

Fundamental changes in thinking weremade during the first six months of theproject, mostly related to the auto-mated material handling field. Changesincluded a move from the use of con-veyor systems towards ACVs, from onecomponent per pallet towards severalcomponents per pallet, from free-standing robots or pick-and-place unitstowards gantry type robots and from theuse of no workbanks to the use of strat-egically placed and sized workbanks.

Many configurations of gantry robotswere considered before deciding that astandard size of 8 x 4 m was theoptimum size for the project (see Fig. 2).

During the specification of the gantryrobots Holset was not confident that thecontrol usually used by the builder wasthe most suitable for the project. Con-sequently, the robots were orderedwithout a controller. This enabled thebuilder to purchase materials andhence the required delivery date wasnot affected.

Holset, with the assistance of a lec-turer from the Department of Engineer-ing Systems of Huddersfield Poly-technic, visited an alternative supplierpreviously used by the robot builder.After the visit it was recommended thata simulator control be purchased tocontinue with the investigation. Thisoffered the advantage of educating theproject team to the control and softwarepossibilities, and later educated assess-ments could be made regarding thefuture project requirements [4].

Eventually the simulator control wasused to specify the details required forthe robot numerical and programmablecontrol software. Later it was used totest the software produced by the sup-plier for compatibility with the enduser's specification.

In the future this control will be usedas a maintenance tool when problemsoccur on the shopfloor. Importantly,Holset will not always have to rely onthe builder for maintenance as theexpertise will be 'in-house'.

Many types of AGVs were consideredbefore rejecting a fork-lift type for thepiggy-back type. This configuration usesa vertical lift table mounted on the vehi-cle to raise and lower the pallets storedon the top of the vehicle (see Fig. 3).

A unique idea considered worthwhileby Holset was to use the ACVs to loadand unload pallets to and from carouseltype pallet stores capable of holdingseveral loaded or unloaded pallets. Thistype of store can be used as either aworkbank for work in progress, a rawmaterial store or a finished part store.However, the store was not available as

54 Computer-Aided Engineering Journal April 1986

standard and consequently had to bespecified between an automationbuilder and the relevant productionengineer.

Owing to the uncertainty of thelayout during the project developmentit became apparent that total flexibilityof AGV programming and guidewirerouting was required. This was onlypossible if the end user was capable ofprogramming and designing the AGVroute layouts for himself.

The design of the AGV transport sys-tem is unconventional in the respectthat there is not a central transport con-troller. Without exception every AGVsupplier considered that an AGV systemcomprised the AGVs under the controlof a central controller [5]. To specify thesystem their first requirement wasalways the plant layout. This is notalways available, as was the case withthe Holset project.

Consequently, Holset had to orderthe AGVs without a transport controland specify with the suppliers a datacommunication link so that AGVinstructions could be communicatedautomatically at a later date.

The distributed traffic control systemis to be developed by the Holset projectengineers.

Simulation is often mentioned whendeveloping the layout of an FMS. Thistechnique was little understood byHolset, but following the fashion ofother FMS projects it was thought itwould be wise to investigate it. Theinvestigation included project workbeing performed at the Polytechnic andthe study of the many software pack-ages available on the market. The con-clusion was that simulation was usefulin producing data regarding system sen-sitivity to variations in product mix andoperation times. It was thought thatsimulation would require valuableresources for a period of time, both inmanpower and capital, before theresults would be sufficiently accurate tobe of any use. Hence simulation was notthought to be necessary at this stage.

Reduced change-over times andimproved workflows were consideredas the highest-priority areas fordeveloping flexibility in the manufac-turing system. Hence a requirement, ofall the machines, was that they could beautomatically changed over and that allnumerical control programs could beselected remotely by an externalcomputer control. Most frequently thisis performed by the use of distributednumerical control (DNC). The problemthat Holset encountered in this case wasthe variety of machine controls. Thiswas inevitable and consequently DNCoperation would have had to be dif-ferent for each different control.

Subsequently it was decided that allprograms that would be required dur-ing automatic change-over would beresident within the machine control'smemory. Every control was specified toallow selection of numerical controlprograms, via digital input lines,through the programmable control ofthe machine and reflect the selectedprogram number on digital outputs.Likewise remote automatic cycle startwas specified to be used to start proven,stored programs.

An essential function required of acell during automatic change-over isthat of remote pallet identification.Many different methods have beenused on existing FMSs; hence each wasinvestigated by the responsible projectengineer. These included bar codereaders, multiple limit switches or prox-imity switches, camera vision systemsand programmable identificationplates. The latter was chosen as themost flexible system and during theduration of the project has becomemuch more popular and less expensive.This system comprises a small identi-fication plate that is attached to the pal-let; via microwave or inductivecommunication across free space thedata held on the plates can be read. Themore sophisticated devices can bere-written at each communication sta-tion, an essential requirement offeringgreater possibilities.

Each machine in the system is fullycapable of being manually loaded andworking as a stand-alone machine.However, the co-ordination of theequipment within each of the auto-mated cells, when they are in the fullyautomatic mode, is performed by a localarea controller (LAC). As with all theother areas of the project, the specifica-tion, the hardware configuration andthe software have been designed by theresponsible project engineers. A typicalcell configuration illustrating the func-tion of the LAC is shown in Fig. 4.

Conclusion

It is thought by the authors that thisapproach to an FMS concept is usefulnot only in terms of manufacturing butas a 'general way of thinking'. This con-cept may be communicated throughoutevery department of the company andbecome a major tool in meeting thecompany's overall business strategy [6].

The people that understand the needfor flexibility can play an important partin the development and communi-cation of the philosophy to ensure oth-ers, working in areas producing no lessimportant components, for final assem-bly and spares, are exposed to the flex-ible way of thinking. Possibly the mostimportant area that should be exposedto the new concept is that of assembly;assembly is the area that pulls the cus-tomer demand through the componentlines.

The concept of flexibility at Holset hasbeen developed among the projectteam over the period of the shaft andwheel project, and this paper discussesthe first two years' progress of a three-year project. The approach to the pro-ject management and specific engineer-ing problems has changed, as theproject has advanced, by an iterativeprocess of discussion and argumentamong the team members. The benefitsachieved by this important procedurecan only be reaped by the end user ofthe FMS if the effort and time are inves-ted by them.

It is thought that there is a case for allend users adopting this approach ofconducting their own project manage-ment and specifying their own detailedrequirements. Equipment suppliers'expertise in designing and manufactur-ing the best equipment shouldobviously always be respected. How-ever, it is the end user himself whoshould decide the type and configura-tion of equipment that is best for hisneeds.

References

1 ASHTON, E. W. S.: 'Changes required in British industry', Proceedings of IMechE, 1984,198B, (6), pp. 83-86

2 GETTLEMAN, K.: 'FMS — alive and innovative in Japan', Modern Machine Shop, 1983, 56,(3), pp. 70-78

3 CHANDLER, J. R., and HOBSON, D.: 'Connecting for FMS —experiences in the building ofan educational system', Computer-Aided Engineering Journal, 1985, 2, (1), pp. 13-20

4 SPOONER, W.: 'Automated handling —the "vital interface" in FMS', Automation, 1984,19,Feb., pp. 133-138

5 'AGV operates with or without computer link', Technology Focus, Dec. 1983/Jan. 1984,pp. 47-49

6 WILDISH, M.: 'Flexibility is a way of thinking', The Engineer, 1983, 9th June, pp. 24-30

P. G. Hudson and S. Webb are with Holset Engineering Company Ltd., PO Box A9, St.Andrews Road, Turnbridge, Huddersfield, West Yorks. HD1 6RD, England, and J. R. Chandleris with the Department of Engineering Systems, The Polytechnic, Queensgate, Huddersfield,West Yorks. HD1 3DH, England.

Computer-Aided Engineering Journal April 1986 55