To start, when building a testing process the essential things are:

• Stakeholder needs and perceptions

• The size of the project

• Project artifacts

• Project activities

• Project synergies

• Minimizing artifacts

• Team dynamics

The first priority: the effort put into testing is proportional to the needs of the stakeholders. If you have a lot of stakeholders with different needs from a testing perspective, you have to consider the minimal effort to satisfy those needs. This may take some prioritization.