systems into /? R. Drake, E. G. john, C. L. Petheram, /? Krabbe and S. N. Ooi describe a simple and efective way for small and medium-sized enterprises to introduce the systems engineering approach ccording to the theory of systems engineering, an orgarusation that operates using a systems approach delivers better engineering through- out all its activities, and the use of systems engineering methods allows the achievement of world-class manu- facturing performance.’ It is often said that education in the methods, tools and techniques of systems engineering will be vital for all engineers of the future. In large manufacturing organisations such as IBM, Xerox and Lucas, specialist systems engineers and departments exist, and are made responsible for promoting and supporting business systems engineering throughout their companies. They can also assume the key task of ensuring that the organisa- tion’~ engineers are trained in the tools and techniques of systems engineering. However, this is not the case in SMEs, which can only survive if they are very lean. A recent survey of attitudes to T Q M issues in 42 SMEs found that ‘The lack of resources in SMEs was a big issue; some managers opined that keeping the company going was hard enough without payng extra staff to do a non-value-adding job12 Paradoxically, it can be argued that, in SMEs, the need for individual engineers to have systems engineering skills is even more acute, since they have far more direct oppor- tunity to re-engineer and improve their systems, and because they tend to have a much wider view of their smaller enterprise. Furthermore, ‘The cost to a small manufacturing company of not changing is normally company c10sure.’~ Fig. I The IDEFo building block Tools A recent article in Manufacturing Engineer4 reported examples of how the Teaching Company Scheme promotes the transfer of people, technology and skills between universities and business and seeks to enhance the competitive- ness of small and medium-sized compa- nies. This is one of the instruments the Manufacturing Engineering Centre, in the Cardiff University School of Engineering, is using to fill the gap left in SMEs without systems depart- ments, and thereby transfer the systems approach to SMEs. The benefits of this activity are mutual as it provides an additional mechanism for training our students in the systems approach. Throughout his works, IEE Past President John Parnaby stresses the importance of simple input-output analysis as one of the core systems- engineering tools. As long ago as 1987, he included it as a core skill to be taught to manufacturing systems engineering students.’ Some form of input-output analysis is a key element of most systems methodologies. Process mapping is an indispensable tool in documenting and understanding a system before analysing and re- designing it, and it requires a graphical representatiom6 IDEFo provides a standard format that satisfies this need. Using it in the work of Teaching Company Schemes is a tangible and relatively simple way of beginning the process of introducing the systems approach into SMEs. IDEFo The US I r Force’s program for Integrated Computer-Aided Manu- facturing (ICAM) yelded the IDEF (ICAM Definition) technique in 1970, after adopting the Structured Analysis & Design Technique (SADT). MANUFACTURINGENGINEER OCTOBER 1998 217
Transcript
systems into
/? R. Drake, E. G. john, C. L. Petheram, /? Krabbe and S. N. Ooi describe a simple and efective way for small and medium-sized enterprises to
introduce the systems engineering approach
ccording to the theory of systems engineering, an orgarusation that operates using a systems approach
delivers better engineering through- out all its activities, and the use of systems engineering methods allows the achievement of world-class manu- facturing performance.’ It is often said that education in the methods, tools and techniques of systems engineering will be vital for all engineers of the future.
In large manufacturing organisations such as IBM, Xerox and Lucas, specialist systems engineers and departments exist, and are made responsible for promoting and supporting business systems engineering throughout their companies. They can also assume the key task of ensuring that the organisa- tion’~ engineers are trained in the tools and techniques of systems engineering.
However, this is not the case in SMEs, which can only survive if they are very lean. A recent survey of attitudes to T Q M issues in 42 SMEs found that ‘The lack of resources in SMEs was a big issue; some managers opined that keeping the company going was hard enough without payng extra staff to do a non-value-adding job12 Paradoxically, it can be argued that, in SMEs, the need for individual engineers to have systems engineering skills is even more acute, since they have far more direct oppor-
tunity to re-engineer and improve their systems, and because they tend to have a much wider view of their smaller enterprise. Furthermore, ‘The cost to a small manufacturing company of not changing is normally company c10sure.’~
Fig. I The IDEFo building block
Tools A recent article in Manufacturing
Engineer4 reported examples of how the Teaching Company Scheme promotes the transfer of people, technology and skills between universities and business and seeks to enhance the competitive- ness of small and medium-sized compa- nies. This is one of the instruments the Manufacturing Engineering Centre, in the Cardiff University School of Engineering, is using to fill the gap
left in SMEs without systems depart- ments, and thereby transfer the systems approach to SMEs. The benefits of this activity are mutual as it provides an additional mechanism for training our students in the systems approach.
Throughout his works, IEE Past President John Parnaby stresses the importance of simple input-output analysis as one of the core systems- engineering tools. As long ago as 1987, he included it as a core skill to be taught to manufacturing systems engineering students.’ Some form of input-output analysis is a key element of most systems methodologies.
Process mapping is an indispensable tool in documenting and understanding a system before analysing and re- designing it, and it requires a graphical representatiom6 IDEFo provides a standard format that satisfies this need. Using it in the work of Teaching Company Schemes is a tangible and relatively simple way of beginning the process of introducing the systems approach into SMEs.
IDEFo The US I r Force’s program for
Integrated Computer-Aided Manu- facturing (ICAM) yelded the IDEF (ICAM Definition) technique in 1970, after adopting the Structured Analysis & Design Technique (SADT).
MANUFACTURING ENGINEER OCTOBER 1998 217
Fig. 2 Activity node tree
IDEF consists of three graphcs-based languages to document functional (IDEFO), information (IDEFI) and dynamics models (IDEFZ) of a manu- facturing system. IDEF2 did not establish itself and has been replaced by simulation. In 1993, the IDEF Users Group created standards for IDEFo and IDEF1, (extended IDEF,) in co-operation with the US National Institutes for Standards & Technology (NET); the IEEE maintains these standards.
IDEFo uses the basic building block shown in Fig. 1 to document not only an activity's inputs and outputs, but also the mechanisms required to perform the activity (e.g. people and machines) and the controls that govern it (e.g. schedules, work instructions, quality
manuals and standards). A system is decomposed in a hierarchical manner into an 'activity node tree' by breaking each activity down into its component activities, then breahng down these component activities and so on, until the required level of detail is reached. 'Activity box decomposition diagrams' link the component activities of a given activity, through their inputs and outputs, to document the flow of information and materials through the system.
Automotive component production
In one Teaching Conipany Scheme, Federal Mogul Sealing Systems (formerly Seal Technology Systems) is developing an automated manufac-
Fig. 3 First-level system activity diagram
turing cell for automotive valve-stem seals. The cell has supervision provided by a feedback control loop containing 100% automated visual inspection and expert knowledge-based SPC.
A find-year manufacturing under- graduate was given the task of performing an IDEFo analysis of the existing quality-management system for valve-stem seals. The student was so successful that he finally produced an IDEFo mapping of the entire valve-stem seal manufacturing process, resulting in the activity node tree in Fig. 2. The top- level system activity l a g r a n is given in Fig. 3. This is decomposed into the activity-box decomposition lagram in Fig. 4. The component activities at this level are further decomposed in their own diagrams, and so on.
A Teaching Company Scheme generally gives an opportunity for re-engineering the industrial partner. Performing the IDEF" analysis allowed the student to identify areas for improvement. He proposed that the production planning (performed by Logistics Control) could be improved by enhancing the information that was fed back to it, on the current status of the production area. A second feedback loop was also proposed, to feed back the actual quantities of raw materials used in production to the cost engineer's database, so that more accurate material cost estimates could be produced based on current performance.
Having introduced IDEFo the next step is to identify where it can be used to good effect within the organisation (and thereby begin to spread the word
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MANUFACTURING ENGINEER OCTOBER 1998 219
of the systeins approach). The student proposed that when a new product is introduced, IDEFo diagrams should be drawn and agreed by all the members of the advanced product planning team. Ths would result in greater confidence in product costing, with the cost engineer working through an agreed, detded map of the manufacturing activities. Proprietary IDEF” software would also support activity-based costing.
Pressed steel quality management
At Europressings, manufacturers of high-quahty steel pressings for the consui-ner electronics industry, a Teaching Company Scheme has been set up to autoinate visual inspection and improve quality control. The first task was to analyse the existing IS09002 accreditation.
By using information from the quality procedures manual and personal investigations, the Teaching Company Associate produced an IDEFo mapping of the quahty management system. As a result of this analysis, reconmendations were made to improve the system. For example, homing in on daily scrap and reject data revealed that the difference between defect symptoins and causes should be clarified. Iniprovements were also proposed for the inspection procedures including (in terms of the
IDEFo mapping) moving some of the procedures fiom one activity to another.
Waste management An area of current concern to manu-
facturers are the Producer Responsi- bhty Obligations (Packaging Waste) Regulations 1997 which have been the subject ofrecent articles in this journal.’ Manufacturers must have a clear under- standing of their manufacturing systems viewed as waste material production system. They need to know where waste arises if they are to design in the correct monitoring and feedback loops, and to know which processes to target to reduce waste.
Ths is a natural application for IDEFo and it provided a final year project for a mechanical engineering undergraduate attached to a Teaching Company Scheme in an SME manu- facturing plastic household products. The project produced the company’s first graphical documentation of where they produced waste in their materials handhng system.
An education tool Our experience has shown that
IDEF” gives novice manufacturing systems engineers a simple framework to adhere to, and as a consequence they are up to speed very quickly In mapping a manufacturing system, they must talk to many of the key actors in the system
to define their individual activities and to get different views of the situation. This leads to debate, understanding and the identification of areas for improvement.
Clearly, it is possible to gain a very good understanding of how the manu- facturing system works. This leads to the view that IDEFO is an excellent tool for induction into a specific company, as well as for systems engineering educa- tion. Where an IDEFo mapping has not been produced before, this method of induction can provide a double pay- back. Where IDEFo diagrams already exist, the method could provide a means of verifying the inductee’s under- standing and the current validity of the existing dmgranis.
An IDEFo analysis of the industrial partner’s manufacturing systems is certainly recommended as the first task for any Teaching Company Scheme; it may be carried out by one of its associates or a project student.
8 Turner, J.: ‘Pack up your troubles’, ibid. 1998, 77 (1)
9 Weaver, A. M., Bennett, J. P, and Byers, N.: ‘Redesigning the order fulfilment process in a small electronics manufac- turing firm using a generic process model’, 12th Nat. Conf. Manufacturing Research, University ofBath, Sept. 1996,
41 (6)
survival’, Mung Eng., 1997, 76 (5)
1997, 76 (5)
pp.151-155
T h e authors aye with the Manufcturing Engineering Centre at Card$ University.
