4.5 The Green Book is intended to provide a comprehensive overview of the assessment process, from the justification for government action through to the development and implementation of lead options. Its aim is to provide non-specialists and senior managers with sufficient information to be comfortable with the structure of a typical appraisal. It should enable them to ask the correct questions, take informed decisions, and become supportive critics of the detailed analysis.
4.6 When assessing value for money it is important that the procuring authority fully considers the possible impacts that its procurement, and any specific impacts under a particular delivery route, may have in the context of wider public sector value for money. Similarly to the treatment of externalities in the assessment of projects under the Green Book, it is important to consider the impacts of undertaking a procurement on other areas of the public sector and the wider economy as a whole. Such procurement-related externalities can be positive or negative. For example, undertaking a procurement may have an impact on the supply side capacity of a particular part of the private sector.