Computersystemen ter ondersteuning en vervanging van industriele persoonlijke verkoop : een studie vanuit de marktkunde, informatica en operationele research

J. Kerkhoven

Research output: Thesisexternal PhD, WU


This thesis concerns computer systems which can either support or replace Industrial Personal Selling (IPS)

The objective of this study is to determine how IPS can be supported or replaced efficiently and effectively by computer systems. IPS is defined here as all activities aimed at face-to-face contact with the intention of realising a transaction. IPS-replacing systems are able to (partially) replace the face-to-face contact. IPS-supporting systems increase the efficiency and effectiveness of the IPS activities.

The parties involved in the face-to-face contact are the buying- and the selling-centre. Mostly, but not exclusively, sales representatives are involved in IPS from within the selling-centre. Members from technical departments are often involved from within the buying-centre, during the selection of products or materials. Members from purchasing departments are involved when suppliers have to be selected.

Five main activities can be distinguished when the operational activities of an industrial sales representative are studied (planning, preparation, conversation, reporting and follow-up). Each of these activities can be considered to a more or lesser extent, for support by means of computer systems.

Because more than one person within a buying-centre can be involved in face-to-face contact with a selling-centre, a classification of the activities of the buying process itself was chosen instead of a classification of the activities of the buyer. Seven phases are distinguished in the buying process (recognition of need, supplier search, definition of characteristics, evaluation of material, acquisition of offers, evaluation of offers and supplier selection).

The connection between the IPS-activities of the selling-centre with the buyingprocess of the buying-centre is made by means of the sales conversation. Six different types of conversation are distinguished (introduction, definition, control, commercial, repetition and fire-fighting). When a selling-centre has to deal with a new buying-centre, the following conversations will be held in order, before a transaction can be realised: introduction, definition, control and commercial conversation. IPS-replacing systems can be developed for each of these four types of sales conversation. The repetition and the fire-fighting conversation are not directly aimed at the realisation of a transaction.

The 4 types of sales conversation can be used as a connection between the 5 activities of the selling-proces and the 7 phases of the buying-process. This integrated interaction- model is used as a framework for the study.

Several Computer Science and Operations Research techniques and models have been used to work out the interaction model. Special attention is given to the mancomputer interface and the usability of Expert Systems and Hypertext Systems. Both types of systems prove to be partially useful for building IPS-replacing systems.

The Operations Research offers a number of tools 'models & algorithms) for developing decision-models for the different types of IPS-replacing systems. Two simple and two complex models have been worked out in detail. A complex lamination problem has been solved by means of a new Integer Linear Programming formulation. The sawing of plastic-sheets has been solved with the cutting-algorithm of Wang.

Several computer systems have been developed for the support or replacement of IPS. A Hypertext System has been built for the introduction conversation. A Decision Support System (EPOS Films) has been built for solving the lamination problem (special form of definition conversation) and a Decision Support System (EPOS Perspex) has been built to solve the sawing problem (special form of commercial conversation). These three systems have only been used as prototypes within the selling-centre. Ile Database Management System EPOS II (replacement definition conversation), the Expert Database System EPOS-F (replacement definition and control conversation) and the Database Management System HOLDAP 4.3 (IPS-support) have been used in practice by many sales representatives and customers. The successor of EPOS II (in 1990 version IV was launched) is being used by many thousands of buying-centres throughout the world. The concept of HOLDAP is being used by many hundreds of industrial sales representatives within the selling-organisation, that has been studied.

The research shows that EPOS II is used on average once every two weeks for 21 minutes by members of buying-centres. In the Netherlands in 1987 EPOS II was in use for approximately 8000 hours. The average industrial sales representative communicated in that year for approximately 120 hours on the same subjects.

EPOS II is being used by the sales representative as an IPS-supporting system. The system especially helps sales representatives with a commercial background who have to operate in a technically complex environment. As a result of the use of EPOS, new contacts with buying-centres have been established, extra requests for offers have been received and more turnover has been generated. The EPOS-concept has been adopted by (almost) all major chemical companies in the world.

The research on HOLDAP 4.3 shows that the amount of information in the buyingcentre increases significantly as a result of the use of HOLDAP. Based on these results an increase in effectiveness can be expected because of improved decision making. The efficiency of the sales representatives is not (yet) positively influenced by the use of HOLDAP and for some sales representatives their efficiency even decreases during the first months of use.

Important side-effects of HOLDAP are an improved and demonstrated willingness of sales representatives to work from home, less need for secretarial support and an increased job-satisfaction.

This study shows that Industrial Personal Selling can be supported or replaced efficiently and effectively in certain areas by computer systems. However there are areas where support or replacement is theoretically impossible, or practically undesirable. There is reason to believe that substantial theoretical and practical improvement in some areas of IPS can be expected in the coming years. Full replacement of IPS by computer systems and thereby the elimination of the need for IPS support , will still remain as fiction for many years to come.

Original languageDutch
QualificationDoctor of Philosophy
Awarding Institution
  • Meulenberg, M.T.G., Promotor
  • Elzas, M.S., Promotor, External person
  • van Beek, P., Promotor, External person
Award date22 Nov 1991
Place of PublicationS.l.
Publication statusPublished - 1991


  • decision analysis
  • computer analysis
  • sales promotion
  • advertising
  • design
  • systems
  • computers
  • operations research
  • marketing
  • management
  • internet
  • software engineering
  • computer networks
  • local area networks

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