What elements should be contained in a validation plan for Excel spreadsheets?

The following elements should be contained in a validation plan for Excel spreadsheets:
•  Specifications (User Requirements Specification, URS)
•  Risk assessment
•  Creation incl. system documentation
•  Test planning (planning of measures, see below)
•  Implementation of reviews and tests
•  Report including description of error handling/the review of all documents/the final evaluation

[GMP Compliance Adviser, Chapter 9.H]