Open issues and good practices:

- How NF-requirements and COTS-based architectures are related.

- How information is obtained from vendors.

- Can we trust in the information available about COTS?

- What’s a good requirement?

- How to know whether using COTS or not.

- How to know if we have skills?

- How do we identify non-negotiable requirements and how do we negotiate others.

- How do we get to match market evolution and system evolution.

- Do requirements play a new role in COTS-based systems?

- Recognize requirements related to customisation and tailoring.

- Recognize market-driven requirements.

- Prioritise requirements for elaborating evaluation criteria.

- Take characteristics of buyers into account.

- Recognize requirements generated during COTS selection.

- Determine a requirements maintenance process when replacing a COTS integrated in the system.

- Recognize requirements about evolution.

- Reevaluate the business case.

- Recognize marketing and people requirements.

- Recognize other non-technical requirements (contract, …).

- Use requirements for early assessment for selection.

- Flexibility of requirements as a target.