A key principle of the NZ Transport Agency Waka Kotahi (NZTA) Business Case Approach (BCA) is the use of informed discussions to ensure that the rationale for a potential investment is adequately understood.

One technique for informed discussion is investment logic mapping (ILM), which is included in the New Zealand Treasury’s guidelines for public sector business cases. ILM ensures ‘that robust discussion and thinking is done up-front, resulting in a sound problem definition, before solutions are identified and before any investment decision is made.’ (NZ Treasury) ILM is used to draw out and test the investment logic, around which the business case is written.

Investment logic mapping information NZ Treasury website(external link)

ILM typically uses facilitated workshops to draw out the investment story. Workshops can be used to understand and agree four critical parts of the logic behind an investment: 

  • the problems that are behind the need for investment
  • the benefits that can be expected if the problem is addressed
  • the best way to respond to the problem and deliver the benefits, and
  • the specific solutions that are needed.

The actual number of workshops needed depends on how complex the investment is, including the levels of risk and uncertainty involved.

There are two main outputs from the initial ILM workshops:

  • an investment logic map, which is used to communicate the investment story on a single page, using plain language
  • a benefits map, which sets out the benefits expected from the investment, including how they will be tracked.

Other outputs may be used, depending on whether you are using ILM workshops to develop your strategic response and/or solutions.

Why use investment logic mapping

All business cases are required to use informed discussion to identify clear, easily understandable problem and benefit statements. ILM is specifically designed to use best-practice informed discussion, so it’s a great way to help you meet this BCA requirement.

For most business cases, ILM will be the best way to quickly understand the problems and benefits that are driving an investment.

For more information on defining problems and benefits as part of the strategic case, see our detailed information.

Defining problems and benefits

Many business cases will use ILM to define and test problems and benefits, but may use other methods to explore alternatives and options, and to identify a recommended solution. You can still use the ILM template to record what’s been decided about the strategic response and the solutions that will be implemented. This is good practice, as it allows you to tell your investment story simply and clearly, on a single page.


ILM uses a series of facilitated workshops to progressively build the logic behind the investment, as shown in the following table:

Workshop Purpose Helps to build (five-case model) Outputs

Problem definition

To define the problems or opportunities that are the reason investment is being considered

Strategic case

Investment logic map (ILM)

Benefit definition

To identify the expected benefits from investment, and show how they will be tracked

Strategic case

Benefits map

Response definition

To identify the preferred strategic response from a range of potential responses

Economic case

(Also relevant to financial, commercial and management cases)

Early assessment analysis tool (EAST)

Multi-criteria analysis (MCA) report

Appraisal summary table (AST)

Solution definition

To confirm the preferred response and define the recommended solution from a range of options

Economic case

(Also relevant to financial, commercial and management cases)

Early assessment analysis tool (EAST)

Multi-criteria analysis (MCA) report

Appraisal summary table (AST)

Which of the workshops you use for your business case will depend a number of factors, including:

  • the pathway you are using to develop your business case
  • how complex the investment is
  • how much risk or uncertainty is involved.

Typically, a minimum of two workshops will be used for less complex investments, these being the problem definition and benefit definition workshops. More complex investments will need to also use response and/or solution workshops to fully explore the available options and recommend a solution.  

Note that even where response and solutions workshops are not used, the BCA still requires business case developers to consider an appropriate range of options and provide the rationale behind the selection of the recommended option.

Defining problems and benefits
Optioneering in the economic case

Who is involved in an ILM workshop?

Successful ILM relies strongly on effective engagement. For each of the workshops, it is important to carefully consider who should be invited, and to be clear on the reasons for inviting them. This guidance should be read together with our guidance on engagement in the BCA.

Engagement and the Business Case Approach

It’s important to get the right people in the room; only schedule workshops when you know those people are available. Problem owners, investors and other stakeholders all need to participate fully in the workshop discussions.

Your engagement planning should have started in the PoE phase, so review the stakeholders you identified there. Consider inviting any partners or key stakeholders you have identified to collaborate with or involve in your engagement plan. Involving people in ILM workshops can be an effective way to collaborate, as this provides opportunities for partners or stakeholders to help shape the investment in a meaningful way.

In particular, remember that Māori have a special relationship with the Crown as Treaty of Waitangi partners and NZTA has a role to develop Māori capacity in decision making. Check your engagement plan to make sure you include any specific needs for engaging with Māori when planning workshops. The NZTA Māori engagement framework, Hononga ki te iwi, may be a useful guide for other organisations as well.

Hononga ki te iwi – our Māori engagement framework

Also, think about the context of the issues involved when selecting workshop participants. A strategic issue could require a different set of participants than a more activity-related/operational problem.

As the business case progresses and you move from one workshop to the next, you may need to involve different participants. Continue using your engagement planning to inform decisions about who to involve in each workshop.

How many participants?

You should aim to keep workshop attendees to a minimum. This helps to make sure the discussion is focused and there is opportunity for everyone present to be heard. It also helps to avoid placing unnecessary demands on busy people.

Depending on the nature of the investment, workshops will typically involve between five to 10 people, although this could be up to 15.

Remember, it’s important to invite participants because you believe they can make a meaningful contribution to the ILM process; inviting people to attend for political reasons or simply to ‘keep them in the loop’ is best avoided.

Key participants

When selecting workshop participants, keep the problem and/or opportunity in mind and remember that the ILM process is not a consultation exercise. It is information gathering, so you need to bring people who are accountable for benefit realisation together with those who hold the most knowledge about the subject. Key participants include:

  • a facilitator
  • the problem owner
  • decision makers
  • investment partners or key stakeholders, and
  • subject matter experts.

Participants should be familiar with the topic and be prepared to actively contribute to the workshops.

Workshop facilitators

Facilitators play a critical role in using ILM successfully. For all but the simplest investments, it is essential to engage a facilitator who is experienced in the BCA and familiar with NZTA’s ILM requirements.

Take time to brief your facilitator on the issue(s) that your business case needs to explore, although avoid pointing them towards pre-determined solutions. Facilitators are expected to be ‘content-free’, that is, have no stake in the outcome of the discussions, and to:

  • guide critical thinking and testing assumptions and positions in the room
  • challenge participants to ensure that each statement can be supported by evidence
  • help participants to tell their investment story clearly and concisely, then express it in plain language and concepts
  • obtain the agreement of participants to the outcome of the discussions.

They may be trained or accredited ILM facilitators, as appropriate. Accredited ILM facilitators are recommended for complex multi-party issues.

List of accredited ILM facilitators on the State of Victoria Department of Treasury and Finance website(external link) 

Problem owners

The problem owner is the person who is accountable for the business problem, and responsible for achieving the benefits.


  • initiate the ILM workshop and provide enough information for participants to gather generic evidence
  • identify the other participants to be engaged
  • decide whether to proceed further, depending on the outcome of the workshop.


Investors need to:

  • understand the case for change, including:
    • the scale of the problems, the trade-off between potential benefits and risks, and where these sit in the wider strategic context
    • whether the investment is sufficiently aligned with the investors’ organisational goals and objectives
  • be accountable for decisions on whether to invest resources to address the problems identified and progress further through the BCA.

Where multiple funding sources are involved, there will be more than one investor. Each co-investor needs to understand why the problems need addressing and what outcomes they are ‘buying’. Recognising each other’s decision pathways and understanding the interdependencies are critical.

Investors’ representatives should have sufficient authority/delegation to confirm the necessary investment for the next phase, or signal the proposal’s viability through their interest in proceeding beyond the strategic case.

Key stakeholders

These are the stakeholders who will be important to the success of the investment. This can include stakeholders who will be significantly impacted by, or be able to influence, the problem. They:

  • may represent members or constituents who use the transport system, such as the Road Transport Association or the Automobile Association, and have a responsibility to participate by sharing their knowledge and insight on behalf of their organisation and/or members
  • often hold senior roles and can contribute to identifying and understanding the problems and benefits at a strategic level, and can contribute supporting evidence.

Subject matter experts

Other participants include people who hold knowledge or specialist skills that are needed to understand the investment, such as people who have a strong understanding of the problem, operational environment or benefits relevant to the business case.

Knowledge holders are expected to support informed discussions with evidence-based views.

What preparation is required?

While it is not expected that new work is done in the lead up to the workshops, participants should come to an ILM ready to take part in discussions and offer their opinion and expertise. This means participants are expected to give some thought to the potential problem or opportunity beforehand and be ready to share any relevant existing work or data they have at the workshop.

A good practice for participants is to canvass others in their team or organisation before they come to the workshop.

What happens at the problem definition workshop?

The problem definition workshop focuses on identifying the problem or opportunity that is the main reason for considering investment. It is designed to help answer the following questions:

  • What is the problem that needs to be addressed (including the cause and the consequence)?
  • Does the evidence confirm the cause and consequence of the problem?
  • Does the problem need to be addressed at this time?
  • Is the problem specific to this investment, or should a broader perspective be taken?

In the workshop, the problem owner sets the scene and introduces the potential investment that has led to the workshop. The facilitator will then lead participants through the process of identifying the main problems or opportunities that are driving the need for investment. By the end of the workshop, the participants will have developed a number of problem statements which will be presented in an investment logic map. The workshop should identify at least one problem and no more than four.

Investment logic map template [PPTX, 59 KB]

Each problem statement:

  • should capture the underlying, or root cause of the problem and its consequence
  • must be supported by agreement that the problem exists and that there is evidence of a correlation between the problem and the consequence – the link between cause and consequence is critical
  • should be compelling
  • is ranked with a percentage, demonstrating what is considered to be the largest problem (with all the percentages adding up to 100%). If any statement has a weighting of less than 10%, you need to consider if it is genuinely a priority for the investment to address.

More information about defining problems and/or opportunities and benefits, and developing problem statements is available on our website and in information sheets.

Defining problems and benefits
BCA Practice Notes 2: How problem statements are used in practice [PDF, 78 KB]
BCA Practice Notes 3: Root cause analysis in business case development [PDF, 120 KB]

What happens at the benefits definition workshop?

The benefit definition workshop is used to identify the outcomes that the investment needs to achieve in order to be successful. It is designed to help you answer the following questions:

  • Have the benefits that will result from fixing the problem and/or opportunity been adequately defined?
  • Are the benefits of high value to the organisation(s), furthering its/their objectives?
  • Will the measures that have been specified provide reasonable evidence that the benefits have been delivered?
  • Are the measures both measurable and totally attributable to this investment?

Aim to hold the benefits workshop around one week after the problem definition workshop, and ideally no more than two weeks. It is good practice to have continuity of participants from the problem workshop, however you may need to make some changes as well. For example, if you have a benefit specialist available, it can be helpful to have them at the benefit workshop.

At the workshop, participants will:

  • review the problems from the first workshop
  • explore the benefits by determining:
    • the benefit that can be expected if each problem is successfully addressed
    • for each benefit, at least one supporting measure that demonstrates how the benefit will be tracked
    • baselines and target values for each measure.

NZTA has developed the Land Transport Benefits Framework, to support quicker and more consistent identification of benefits that are relevant to transport. For all business cases that seek funding through the National Land Transport Programme, it is a requirement to consider benefits and measures from the benefits framework. Alternative benefits and measures can only be used if they are materially different from those in the framework. Alternatives may be finalised after the workshop in consultation with NZTA investment advisors.

Note that other community benefits linked to non-transport outcomes can be reflected alongside transport benefits in the ILM and benefits map. For more information about NZTAs benefits management framework see our guidance.

Benefits management guidance

The benefits and measures identified in the workshop are recorded on a benefits map.

Benefits map template [PPTX, 64 KB]

The benefits map is a key document as it is used throughout the rest of the business case, for example to derive investment objectives, evaluate options and to guide benefit realisation under the management case.

How are workshops used to define the response and solutions?

Under the ILM approach, facilitated workshops can also be used to:

  • define the strategic response, and
  • identify the recommended solution(s) that will be used to address the issues identified in the strategic case.

Further details of how workshops can be used to explore the strategic response and the solution are provided in the relevant page for each business case development phase.

Programme business case phase
Single-stage business case phase
Indicative business case phase
Detailed business case phase

What happens after the workshops?

After the workshops have been held, the facilitator will typically:

  • create a plain-English story that summarises the workshop discussion
  • prepare updated versions of the ILM/problem definition and benefits maps
  • email these documents directly to participants, asking for feedback
  • include observations of strengths and weaknesses in the email and, if possible, also include the list of issues.

When they have received participant feedback, the facilitator will, as relevant:

  • finalise the ILM/problem definition and establish next steps
  • finalise all the discussion and the ILM/problem definition and benefits maps within 48 hours of the final workshop.

The maps form a key input into developing a strategic case. If the result of the workshops is a decision to proceed to a strategic case, it should progress promptly.

What are the outputs?

The main outputs from problems and benefits definition workshops are simple, single-page flowcharts that tell the story of a possible investment and expose its underpinning logic. They are the start of the conversation about whether it is necessary to invest time and money into looking into the problems or opportunities for potential investment.

A map format is not always necessary, but the problems, opportunities and benefits must be clearly articulated however they are presented.

Typical outputs from each workshop include:

  • Investment logic map: A single-page representation of the logic that underpins the investment, showing the problems, benefits, responses and solutions. The investment logic map is built progressively, starting with the problem definition workshop, and updated as the workshops progress.
    Investment logic map template [PPTX, 59 KB]
  • Benefits map: A single-page document that details the benefits that the investment needs to achieve, their measures, baselines and desired targets.
    Benefits map template [PPTX, 64 KB]
  • Early assessment sifting tool (EAST): The EAST tool can be used to apply a ‘coarse sift’ to alternatives and options. This can be helpful where there are a lot of options, to reduce the number of longlisted options that are evaluated using MCA. Use of the EAST tool is optional.
    Early assessment sifting tool
  • Multi-criteria analysis (MCA) report: MCA can be used to compare different alternatives and options and assist informed discussion between investors and stakeholders to help inform decisions about the preferred response (response definition workshop) or recommended solution (solution definition workshop). MCA allows a range of criteria to be used to evaluate the options available, before a decision is made about the best value for money option. Typically, a report is produced detailing the options considered, criteria, scoring and outcome of the analysis.
    Multi-criteria analysis
  • Appraisal summary table (AST): The AST summarises the impacts of a shortlisted option compared with a do-minimum option. It is used to give decision makers a clear understanding of the benefits associated with each shortlisted option compared to the do-minimum. Depending on the development pathway being followed for your business case, AST is used to summarise shortlisted options in the PBC, SSBC or IBC and DBC phases.
    Appraisal summary table

How do I know my ILM is fit-for-purpose?

The answer to this will depend on which phase you are working on, how complex the investment is, and how much risk or uncertainty is involved.

However, there are a few things that can help you, including:

  • Talk to your NZTA investment advisor. It’s important to work with your investment advisor throughout the business case. They will be able to help you get the level of detail right and avoid missing any important steps.
  • After each of the four stages, check against the relevant questions from the 16 questions, which have been developed to help business case practitioners understand when they have done enough. In general terms:
    • the first eight questions relate to problem and benefit definition
    • questions 9–12 relate to the strategic response, and
    • questions 13–16 relate to the solution.

How to self-assess your business case

Resources and further information



Information sheets

Need support?

Contact your NZTA investment advisor or email the Business Case Process team at businesscaseprocess@nzta.govt.nz