Written Schemes of Investigation (WSI) are documents which define the scope and standards of archaeological or other heritage studies (for example field work or building recording). WSI generally relate to projects which are at planning application stage. A parallel document-type, Written Schemes of Historic Environment Mitigation (WSHEM), relate to the measures required for a consented development, usually in response to planning conditions.

Archaeological Services can produce quality WSIs which meet the highest of professional standards, working with clients, in consultation with Archaeological Curators and advisors to local authorities, to secure reasonable and proportionate scopes of work throughout all stages of the development process that result in efficient approval and cost-effective solutions.