Debriefing after completing a business case provides an important opportunity to learn from your experience, and then to use those lessons learned to improve the process, both for your organisation and for the wider sector.

During our Business Case Refresh consultation in 2022 there were high levels of support for incorporating debriefing into the Business Case Approach (BCA) in order to record and centralise lessons learned.

To start this change, we have developed this guidance and process to help business case teams to debrief effectively. While debriefing is not mandatory, we expect NZ Transport Agency Waka Kotahi (NZTA) business cases to debrief, and encourage approved organisations to begin incorporating this step into their business case processes. This debriefing process should complement, not replace, any existing debriefing or lessons learned processes that your organisation may already be using.;

Why is debriefing important?

Holding a formal debriefing session after completing a business case provides an opportunity to reflect on how the business case went, celebrate successes and learn from challenges to help set future business cases up for success.

The purpose of debriefing is to:

  1. focus on opportunities for improving the business case development process, including the project scope and procurement approaches
  2. highlight examples of good work and areas of success
  3. proactively share findings with the project team, organisations, consultants and the wider industry to support upskilling and an increasing level of quality of business cases.

Debriefing sessions will also support the improvement of the BCA by providing a regular process to provide general and specific feedback. The ultimate outcome will be to improve our business case processes for everyone.

When to debrief

Debriefing follows the completion of a business case, after For NZTA business cases, this will be after it has been endorsed by the Delegations Committee.

What happens at the debriefing session?

The debriefing session should be an open environment to enable better sharing of ideas and learning between those working on business cases. It should provide value to all those involved the business case process.

While the session can be relatively informal, and centred on a continuous improvement mindset, it is important to recognise that some of the discussion could be sensitive and include contentious or challenging topics. Because of this, it’s important the feedback is treated with the appropriate respect.

If the topics that need to be discussed are particularly sensitive, consider whether the debriefing session is the correct approach. For NZTA business cases you can seek guidance from the Assurance team.

A facilitator can use the guide to debriefing questions to help the discussion.

Business case debriefing session questions guide [DOCX, 147 KB]

Who should be involved in debriefing?

The project manager determines who should attend the debriefing session, but it should include representatives from the client organisations and consultants to give a broad range of perspectives in the feedback. Consider including the project manager, design lead, investment advisor, appropriate subject matter experts and one or more representatives from the consultant(s).


Although the session should be relatively informal, it should be facilitated by someone with the appropriate skills to foster open dialogue and encourage participation in a potentially challenging environment. There is no set role that should be the facilitator, however, in many cases it is reasonable that the investment advisor or transport planner could facilitate the discussion, or someone else from your organisation could be used to provide some independence.

Organisations may wish to provide appropriate training to ensure facilitators to develop the skills needed to optimally facilitate debriefing sessions. These skills will be transferable and beneficial to their day-to-day roles.

Scaling the debriefing to your business case

Following the BCA principle of fit-for-purpose effort, you should scale the debriefing process to be appropriate for your business case.

For example:

  • Simple or small-scale business case. The debriefing session could involve a simple exchange of emails and/or a brief meeting between relevant parties (for example the project manager, transport planner and consultant business case lead).
  • Medium-scale business case. Debriefing could involve an informal meeting with several key project members. Discussion could be recorded and transcribed into a set of agreed notes.
  • Medium- to high-scale and complexity business case. Debriefing could involve a workshop with key project members and an independent facilitator.
  • Highly complex or contentious business case. Seek advice from your organisation’s assurance team as to an appropriate method of debriefing.

The debriefing process

The steps below are a guide for how to run the debriefing process. However, the process is flexible and scalable to fit the characteristics of each individual business case.

1. Complete business case

This means that:

  • the business case is drafted (including SME input and business case / investment advice)
  • IQA is drafted and supplied to project team
  • comments and feedback have been considered
  • the IQA is finalised, provided to the project team and attached to project approval paper.

2. Business case is reviewed by the appropriate authority, and decision received

3. Project manager initiates a debriefing session

The project manager needs to determine:

  • the appropriate form of the review, considering the scale and complexity of the business case
  • who should attend
  • if a facilitator is needed and, if so, who should it be.

4. Hold debriefing session

The key areas of discussion include:

  • what worked well (and why)
  • what was not a success (and why)
  • any opportunities to improve.

The debriefing session questions guide provides some example questions that can help guide discussion.

Business case debriefing session questions guide [DOCX, 147 KB]

5. Record discussion and share with participants

The project manager should provide the opportunity for participants to add and/or challenge content before the debriefing session summary is finalised.

6. Finalise debriefing session summary and distribute it to participants

7. Share debriefing summary with the Business Case Process team at NZTA

Send your report to

What will happen with the debriefing reports?

The Business Case Process team will manage a filling system for the reports and periodically report key themes internally, to stakeholders, and to wider industry via forums such the BCA community of practice. We expected this will occur semi-regularly (such as biannually) once a sufficient number of business cases were included in the sample to provide both a good understanding of key themes and some anonymity to projects and respondents.

Resources and further information


Online learning

Need support?

Contact your NZTA investment advisor or email the Business Case Process team at