 make compromises in their IT strategy. If they are willing to adopt product-based offering available for some of their core processes and outsource their in-house software development activity, they will have to use external IT consultants for tailoring customized software for the other processes, to which there exists no suitable software products. This development explains the high share of external IT spending even if there are market segments with a reasonably high volume of product-based business. Altogether, this further implies that using a vertical soft- ware market and the enterprises within it as the units of analysis is essential for understanding a vertical software industry. Part III analyzed some of the reasons which are likely to direct or hinder the further evolution of the vertical software industry (OSS/BSS) causing disconnection with the vertical industry of telecom operators. These include the analysis of system modularity stating that the systems are integrated along the main business processes handling the bulk of the information processing volume. The minimum number of operators as the customers for OSS/BSS software vendors was also estimated and verified with market data. Most importantly, the continuous evolution of telecom technologies seems to be a major reason for a need to renew software interfaces at a pace not possible for small software companies. In addition, IPR strategies and SIM- locking can slow down the evolution of the software market. Part IV presented a Delphi analysis, which was used for validating alternative future miniscenarios for the OSS/BSS market. The results were summarized as a Manager's Toolbox in Chapter 15 for business users. Chapter 16 outlines a method for repeating this research in some other vertical industry as well as for extending the Manager's Toolbox presented or creating a similar Toolbox for another vertical software industry. Evolution of Telecom Operator Software Industry: Conclusions and Future Telecom Operator Market The telecom operator softwa