Complexity and proportionality

All of the principles and policies set out in this Playbook should be applied proportionately to the complexity and significance of each project or programme.

Contracting authorities should have systems and governance forums in place to determine their most important contracts. Typically, the greater the complexity, cost and risk, the more important a project or programme will be and the more robust and rigorous a process is required to successfully set up, procure and manage it.

The principles set out in the HM Treasury approvals process provide a guide for characteristics of more complex and significant programmes and projects that:

• are above delegated authority limit and could create pressures leading to a breach in departmental expenditure limits or administration cost limits

• would entail contractual commitments to significant levels of spending in future years for which plans have not been set

• could set a potentially expensive precedent

• are novel and contentious, or could cause significant repercussions, posing risks to the public sector

• require primary legislation, or Treasury consent as a statutory requirement

In addition, the IPA has developed a Delivery Environment Complexity Assessment as part of the IPA Routemap to assess complexity.

For more complex and significant projects, contracting authorities should:

• consider a greater proportion of 'front end loading' by implementing robust project planning, design and preparation for project execution in the early stages of the project and programme lifecycle

• contract for ESI

• consider an alliancing-based approach

• develop a detailed and multi-stage Should Cost Model covering both whole life cost and schedule

• embed a whole life carbon approach early in the identification and selection of solutions

• have an expert or practitioner-level contract manager in place

Chapter 4 provides further guidance on compliance and approvals.