Justification of a theory-building case study

At the beginning of this study it was known which kind of dependent concept was sought, namely the variation in the composition of the teams of representatives of the buying company that interact with rep- resentatives of the supplying company. It was, however, not known what the relevant concept was by which this variation could be charac- terized, nor was there a proposition available which linked the varia- tion of the values of this as yet unknown concept to different types of services that were bought. No information is given about whether any “exploration” as meant in Chapter 3 was attempted. The results of the round-table meeting with company representatives, mentioned in 9.2.8, suggest that an exploration could have been quite successful. These company repre- sentatives might have been able to generate versions of the proposi- tions that have been built in this study. Because the type of service that is bought by a company cannot be experimentally manipulated, it is clear that an experiment was not feasible.

9.3.2 Candidate cases

Our advice is to find a candidate case for theory-building research in small populations in the theoretical domain. The proposition that had to be built in this study then still a proposition with an empty space concerned the domain of communications between buyers and sellers of business services after the purchase of such a service. Because the authors of this study had built contacts with a large network of pur- chasing managers in the Netherlands, they were able to identify a number of Dutch companies that had been buying services, and they knew that they might be able to collect data on interaction patterns regarding these purchases by getting access through these purchasing managers. Within this set of Dutch companies, the search for candidate cases was limited to large companies with professional purchasing organiza- tions that are service companies themselves. This choice of large com- panies with professional purchasing organizations made sense indeed, if the aim of the study was not just to find relations between type of service and type of interaction in the broad spectrum of all instances of a purchase of a service, but rather was more specifically aimed at find- ing such relations in companies with much experience in purchasing services.

9.3.3 Case selection

The criterion of maximum variation of the value of the known concept required that at least two instances of a purchase per type of service should be selected. It would have been acceptable for this theory-building study to select cases i.e. instances of a service purchase from the small population of all such purchases in one company. This would enhance the chance of finding specific relations between type of service and kind of representative, but the resulting propositions would next need to be tested in other groups or populations i.e. other companies and types of companies. It could be possible that the propositions built in the study would only hold in the one company in which they were found. In order to avoid this scenario, cases were selected from two different companies. By doing this, the chance of finding an effect of the type of purchased service on the kind of representative involved in the communication was reduced which could be overshadowed by the effects of differences in policy between the companies in the way they select representatives but at the same time it increased the likelihood that found propositions would be robust in replication tests.

9.3.4 Extracting relevant evidence

Data were collected by asking informants which departmentsfunctions were involved in managing the ongoing supply after the purchase of a service. The answers that were obtained are listed in Table 9.7. In order to translate these various answers into values of one concept, the seven value-creating functions described by Porter 1985: 45–48 were applied. An eighth value of this concept was added based on the data that had been collected, namely the value “internal customer” i.e. a representa- tive of the users of the service as distinct from persons with a functional expertise. The result of the study thus far is depicted in Figure 9.4. Type of service Representatives of different value- creating functions according to Porter ??? Independent Dependent Figure 9.4 Proposition with discovered dependent concept