Selecting sourcing options for software assets and components is an important process that helps companies to gain and keep their competitive advantage. The sourcing options include: in-house, COTS, open source and outsourcing. The objective of this paper is to further refine, extend and validate a solution presented in our previous work. The refinement includes a set of decision-making activities, which are described in the form of a process-line that can be used by decision-makers to build their specific decision-making process. We conducted five case studies in three companies to validate the coverage of the set of decision-making activities. The solution in our previous work was validated in two cases in the first two companies. In the validation, it was observed that no activity in the proposed set was perceived to be missing, although not all activities were conducted and the activities that were conducted were not executed in a specific order. Therefore, the refinement of the solution into a process-line approach increases the flexibility and hence it is better in capturing the differences in the decision-making processes observed in the case studies. The applicability of the process-line was then validated in three case studies in a third company.