This topic includes research into the current status of the use of portfolio methods in Dutch purchasing practice.
Portfolio methods and techniques are used by companies to design and implement differentiated supplier strategies. Through these techniques companies decide a) what number of suppliers to source from for a certain product category, b) what type of relationship to pursue (arm’s length or partnership) and c) what contractual relationship to strive for.

The research includes a thorough literature survey, three in depth case studies related to different companies and purchasing structures, a large scale survey among 248 Dutch manufacturing companies. Conclusions are that about 60% of Dutch industry actually uses some form of portfolio method in their relationships with suppliers and that different variations on known supplier strategies are being applied. Adopters of portfolio methods discriminate positively in terms of professionalism from non-users.

Kees Gelderman (Open University) is the co-ordinator of this project. His work was published in his PhD-thesis ‘A Portfolio Approach for the Development of Differentiated Supplier Strategies’.