Pre-implementation and implementation phases and the business case

The pre-implementation and implementation phases are both important in readying a project for delivery.

In theory the business case phases are now over. The endorsed business case informs the steps and decisions you will make as you progress through the pre-implementation and implementation phases.

However, in practice you will be confronted with new information during these phases that will challenge the assumptions and decisions of the endorsed business case. Using the skills and principles of the Business Case Approach (BCA) will help you navigate these issues during these phases. In the most extreme situations, projects might go back to an earlier business case phase to revisit the business case.

What is the purpose of the pre-implementation and implementation phases?

Both phases are to ensure that the project is successfully delivered and meets the standards and strategic objectives outlined in the approved business case. Pre-implementation readies the project for implementation, and implementation ensures the project is delivered.

The following diagram shows where the pre-implementation and implementation phases typically fit in the framework of business case development pathways.

View larger image [JPG, 218 KB]

What happens during the pre-implementation and implementation phases?

The pre-implementation phase is when everything is set up for successful implementation, including the consenting, property and detailed design phases of a project.

If the solution includes construction, this takes place during the implementation, along with the associated management and surveillance of the project.

For Waka Kotahi projects, guidance on the pre-implementation and implementation phases and related technical standards is available on our website and in the State highway professional services contract proforma manual (SM030).

State highway professional services contract proforma manual (SM030)

How do the pre-implementation and implementation phases relate to the business case?

During these phases you need to ensure that:

  • any substantial changes are captured in the business case
  • areas where further business case work is required are highlighted.

When developing projects through the pre-implementation and implementation phases, you may identify additional risks that impact the cost, timeframes, outcomes or significance of a project. When this happens, it is important to get in contact with your investment advisor to ensure that the proposed scope is still the best way forward.

Even if you don’t trigger the thresholds to require formal price-level adjustments (PLAs) or cost-scope adjustments (CSAs), it is important to keep the governing body of the project (as described in the management case) informed of developing and resolving risks and uncertainties. The investment logic map contained in the business case will guide you when navigating through issues as they arise – Is the solution still addressing the problem statements? Will the outcomes still meet the investment objectives? Is this still a value-for-money solution?

Management case
Strategic case

For more information about the price-level adjustment (PLA) or a cost-scope adjustment (CSA) process for Wakai Kotahi process, download the variation guidance below.

Waka Kotahi variation request process, procedures, and checklist [PDF, 451 KB]

When you could use an implementation business case

For some projects funded outside of the National Land Transport Fund, you may choose to follow the Treasury Better Business Cases process.

Better Business Cases(external link)

This approach includes an implementation business case. This phase recommends a preferred supplier (for implementation) and seeks approval from decision-makers to enter commercial contracts for the provision of the endorsed option. The implementation business case forms the basis of the project management plan or similar management/control document for the delivery phase of the project.

Better Business Cases project implementation business case(external link)

Stakeholder engagement during the pre-implementation and implementation phases

During the pre-implementation phase, engagement is to:

  • refine and confirm the endorsed option, including statutory consultation
  • support landowners and involve partners and the community in construction management plans.

During the pre-implementation phase, engagement mainly relates to construction plans and mitigation.

Find out more about engagement in the BCA on our webpage.

Engagement and the Business Case Approach

Resources and further information


Need support?

For business case-related queries during pre-implementation or implementation phases, contact your Waka Kotahi investment advisor or email the Business Case Process team at