The business case occupies a peculiar place in organisational life. It is simultaneously one of the most important documents a leadership team will produce and one of the most frequently misunderstood. In many organisations it is treated as a gateway ritual: a document to be written to unlock approval, which is then filed and rarely consulted again once the project begins. In others it is treated as a financial argument alone, a vehicle for presenting a cost-benefit calculation and a projected return on investment.
Both of these approaches miss what a genuinely good business case is and what it is for. A good business case is not primarily a document. It is a structured decision-making tool that helps an organisation answer three fundamental questions with rigour and honesty: should we do this at all, are we doing it in the right way, and do we have the capability to deliver it? When a business case answers those questions well, it does not simply unlock investment. It becomes the reference point against which delivery decisions are made, the standard against which outcomes are eventually measured, and the earliest test of whether an organisation is ready to undertake what it is proposing.
Understanding what a good business case looks like, and how to scale that standard to the size and nature of the organisation producing it, is one of the most practically valuable capabilities in delivery. It is also one of the most consequential, because the quality of a business case determines not just whether a project starts but whether it finishes well.
Why So Many Business Cases Fall Short
The most common failure in business case development is not dishonesty but incompleteness. Business cases fail to convince, fail to guide delivery, or fail to hold up under scrutiny for a small number of predictable reasons.
- The problem is poorly defined. The case describes the solution in detail but gives inadequate attention to the problem it is solving. Without a clear, evidence-based account of the current state and its costs, the argument for investment rests on assertion rather than analysis.
- Options are not genuinely appraised. A business case that presents one option alongside a straw man and a do-nothing alternative is not an options appraisal. It is a recommendation dressed as analysis. Decision-makers deserve a genuine assessment of the realistic range of approaches.
- Assumptions are not tested. Cost estimates, benefit projections, and timelines are presented as facts rather than as assumptions that carry uncertainty. The absence of sensitivity analysis is one of the clearest signs that a business case has been built to justify a decision already made rather than to inform one yet to be taken.
- The management case is absent or superficial. The financial and strategic arguments are developed with care while the question of whether the organisation can actually deliver the proposed initiative receives a paragraph. Delivery capability is at least as consequential as economic value, and a business case that neglects it is not complete.
- It is not scaled to its audience or context. A fifty-page document produced for a small business seeking to replace its CRM system is as problematic as a two-page brief produced for a complex, multi-year public sector transformation. Proportionality is not a concession to laziness; it is a professional discipline.
The HM Treasury Five Case Model: A Framework Built for Rigour
The HM Treasury Five Case Model, developed for use across UK public sector investment decisions and increasingly adopted in large private sector and regulated environments, provides one of the most comprehensive and durable frameworks for structuring a business case. Its value lies in the discipline it imposes: by requiring that an investment be justified across five distinct dimensions, it prevents any single argument from carrying a decision that it is not sufficient to support alone.
The five cases are sequential in logic, though they are developed and tested together. The strategic case must be established before the economic case is worth developing. The economic case must be credible before the commercial and financial cases are worth detailing. And the management case must demonstrate that the organisation is capable of delivering what the other four cases have justified.
| Case | Central question | What a strong case demonstrates |
|---|---|---|
| Strategic | Is there a compelling case for change? | Clear alignment to organisational strategy; problem well-defined; options genuinely appraised |
| Economic | Does it represent value for money? | Robust cost-benefit analysis; realistic assumptions; sensitivity analysis; preferred option justified |
| Commercial | Is it commercially viable? | Procurement approach defined; market tested; contract and risk allocation considered |
| Financial | Is it affordable? | Full funding confirmed; cash flow modelled; impact on balance sheet understood |
| Management | Can it be delivered? | Delivery capability demonstrated; governance designed; risks and dependencies visible |
The strategic case is the foundation. It answers the question of whether there is a genuine and well-evidenced need for change, whether the proposed initiative is aligned to the organisation's direction and priorities, and whether the problem being solved is the right one. A strategic case that is vague about the problem or that describes alignment to strategy in general terms without demonstrating it specifically is not a strategic case. It is a preamble.
The economic case is where most of the analytical rigour is concentrated. It presents the options that have been considered, the methodology used to assess them, the cost and benefit profiles of each, the preferred option and the reasons for its selection, and the sensitivity of the analysis to changes in key assumptions. In a robust economic case, the preferred option earns its position through analysis rather than winning by default.
The commercial case addresses the question of how the proposed initiative will be procured and contracted. For organisations working with external suppliers, it considers the market, the contractual structure, the allocation of risk between client and supplier, and the protections available if delivery falls short. For internally delivered initiatives, it considers resourcing, capability, and the make-versus-buy decisions that underpin the delivery model.
The financial case translates the economic case into a funding plan. It confirms that the investment is affordable within the organisation's financial position, models the cash flow implications over the delivery period, and addresses the impact on the organisation's balance sheet and ongoing cost base. A financial case that relies on optimistic assumptions about future funding or that does not account for the full lifecycle cost of the proposed solution is a financial risk dressed as a financial plan.
The management case is the one most frequently underinvested in, and the one whose weakness is most reliably associated with delivery failure. It should demonstrate that the organisation has a credible plan for delivery: a governance structure designed for the scale and complexity of the work, a realistic programme plan, a benefits realisation approach that extends beyond go-live, a risk management strategy, and an honest assessment of the organisational capability required to deliver and to sustain the proposed change.
Organisational Alignment: What the McKinsey 7-S Model Adds
The HM Treasury Five Case Model provides the structural framework for a business case. The McKinsey 7-S Model provides a complementary lens for the most demanding question in that framework: whether the organisation is genuinely capable of delivering and sustaining what it is proposing.
The 7-S Model identifies seven interdependent elements of organisational effectiveness: Strategy, Structure, Systems, Shared Values, Style, Staff, and Skills. In a business case context, these seven elements provide a diagnostic framework for the management case. A management case that can demonstrate alignment across all seven is far more credible than one that addresses only governance structure and programme plan.
Strategy
The business case should demonstrate that the proposed initiative is derived from and consistent with the organisation's strategy, not merely described as aligned to it. This means tracing the causal chain from strategic priority through to the specific investment being proposed, and demonstrating that the investment addresses a genuine strategic gap rather than a preference or a fashion.
Structure
The management case should address how the programme will be governed and how it fits within the existing organisational structure. Who is accountable? Where does decision-making authority sit? How are dependencies between the programme and the rest of the organisation managed? A proposed governance structure that is not connected to the existing accountability framework will generate confusion and conflict rather than clarity.
Systems
What processes, technologies, and reporting mechanisms will support delivery? Will existing systems accommodate the change, or will they need to be adapted? What information does the governance structure need to function, and how will that information be generated, validated, and distributed? A management case that proposes a governance model without specifying the information and reporting systems that support it is incomplete.
Shared Values
This is the 7-S element most frequently absent from business cases, and its absence is revealing. The proposed initiative will land in an organisational culture that has values, habits, and norms built over time. A business case should be honest about whether those values are conducive to the change being proposed, and if they are not, about what the plan is for addressing the gap. An initiative that requires a culture of transparency to function but that is being proposed to an organisation with a history of managing perception rather than reporting reality has a risk in its management case that is not visible in its risk register.
Style
Leadership style shapes the conditions in which delivery either accelerates or stalls. A business case that proposes a complex transformation in an organisation where leadership is risk-averse, where decisions escalate rather than being made at the appropriate level, and where challenge is discouraged should acknowledge those conditions explicitly and address them in the change management plan. To ignore them is not to eliminate the risk; it is to disguise it.
Staff and Skills
The management case should provide an honest assessment of whether the organisation has the people and the capabilities required to deliver the proposed initiative. This includes the delivery team, the programme leadership, the receiving organisation that will operate the outputs, and the senior sponsors who will govern the work. Where gaps exist, the business case should specify how they will be addressed: through recruitment, through development, through partnership, or through the engagement of external support. A management case that asserts sufficient capability without demonstrating it is an assertion rather than a case.
The Discipline of Scaling: Proportionality Is Not a Compromise
One of the most important and least discussed aspects of business case quality is proportionality. The standard for what constitutes a good business case is not the same for a small owner-managed business seeking to invest thirty thousand pounds in a new system as it is for a national infrastructure programme seeking approval for three hundred million. Applying a full Five Case Model to the former is not rigorous; it is disproportionate, and disproportionality in either direction undermines the quality of the decision it is supposed to support.
Proportionality does not mean reducing rigour. It means applying the appropriate level of rigour to the scale, complexity, risk, and strategic significance of the investment in question. A small business still needs a clear account of the problem, an honest assessment of the options, a credible financial plan, and a realistic view of whether it can deliver the proposed initiative. It does not need a formal procurement strategy, a sensitivity analysis across multiple discount rates, or a programme-level benefits realisation framework. These are tools designed for a different scale of decision and a different accountability environment.
| Organisation type | Typical scope | Appropriate format | Key emphasis |
|---|---|---|---|
| Small / owner-managed | Single site; limited resource | 2 to 5 page structured brief | Strategic rationale; affordability; owner risk appetite |
| Mid-size / growing | Multi-team; scaling operations | 10 to 20 page business case | Economic value; commercial viability; delivery capability |
| Large / complex | Multi-site; regulated; public-facing | Full Five Case Model document | All five cases; governance design; benefits realisation plan |
| Public sector / regulated | Publicly funded; scrutinised | HM Treasury / IPA standard format | Value for money; accountability; assurance gateway readiness |
Small and Owner-Managed Organisations
For a small business, the business case is often a structured conversation rather than a formal document. Its purpose is to discipline the thinking of the owner or leadership team, to surface assumptions that might otherwise remain implicit, and to provide a basis for a funding conversation with a bank, an investor, or an internal budget holder. It should be concise, direct, and focused on the three questions that matter most at this scale: does this solve a real problem, can we afford it, and do we have the capability to make it work? A well-constructed two to five page brief that answers those questions honestly is a better business case than a twenty-page document that buries the same three answers in the language of formal appraisal.
Mid-Size and Growing Organisations
As organisations grow in complexity, the business case needs to grow with them. A mid-size organisation pursuing a significant investment will typically have multiple stakeholders with different perspectives on value, risk, and affordability; external partners or suppliers involved in delivery; and a governance structure that requires formal sign-off at more than one level. At this scale, the Five Case Model provides a useful structural reference even if not all five cases require the same depth of development. The economic and management cases, in particular, deserve substantive investment because the cost of a poor decision at this scale is genuinely consequential.
Large and Complex Organisations
For large organisations, regulated entities, and public sector bodies, the full rigour of the Five Case Model is appropriate and in many cases mandatory. Investments at this scale affect large numbers of people, consume significant public or shareholder resource, and carry reputational and regulatory risk that demands the highest standard of appraisal. The Infrastructure and Projects Authority in the UK publishes guidance on the application of the Five Case Model to major projects, including assurance review standards that provide an external check on business case quality before investment is committed.
Crucially, scaling also applies in the opposite direction. An organisation that consistently produces brief, informal investment briefs for decisions of genuine strategic significance is not being agile; it is being imprecise. The cost of an under-developed business case in a large or complex organisation is not the time saved in its preparation; it is the cost of the delivery problems, the governance failures, and the benefit shortfalls that flow from decisions made without adequate analysis.
What a Good Business Case Actually Looks Like in Practice
Across all scales and all sectors, the business cases that earn investment, survive scrutiny, and guide delivery well share a consistent set of characteristics.
- The problem is stated before the solution. The document opens with a clear, evidence-based account of the current situation, the costs and consequences of not acting, and the strategic imperative for change. The proposed solution is presented as a response to that diagnosis, not as the starting point.
- Options are genuinely compared. The preferred option is shown to be preferable to realistic alternatives, not to a do-nothing baseline and an obviously inadequate alternative. The criteria for comparison are stated and applied consistently.
- Assumptions are visible and tested. Key assumptions about costs, timelines, benefits, and risks are stated explicitly. Sensitivity analysis shows how the case holds up if those assumptions prove optimistic. The reader can form their own view rather than accepting the author's conclusions on faith.
- Benefits are specific, owned, and measurable. The business case names the benefits, quantifies them where possible, assigns ownership to specific individuals, and sets out how and when they will be measured. Vague references to efficiency gains or improved capability are not benefits; they are aspirations.
- The management case is as developed as the economic one. Governance, delivery capability, risk management, change readiness, and benefits realisation are all addressed with the same rigour applied to the financial analysis.
- It is written for its reader, not for its author. A business case produced for a board of non-executive directors should be written differently from one produced for a technical investment committee. The level of detail, the language used, and the questions addressed should reflect the knowledge and the decision-making responsibility of the intended audience.
- It remains a living reference. A good business case is not archived after approval. It is the document against which delivery decisions are tested, against which scope changes are evaluated, and against which the programme's ultimate success or failure is measured.
The Hervey Dickens Perspective
The business case is the moment at which an organisation's ambition meets its analytical discipline. Done well, it provides clarity, builds confidence, and creates the shared understanding that sustains a programme through the inevitable difficulties of delivery. Done poorly, or done at the wrong scale for the context, it sets a programme on a path toward the kind of delivery problems that are expensive to fix and difficult to explain.
At Hervey Dickens Consulting, we support organisations across the public and private sectors in developing business cases that are rigorous, proportionate, and genuinely useful. That means applying the structural discipline of the Five Case Model where the scale and complexity of the investment warrants it, using the 7-S framework to ensure the management case reflects organisational reality rather than aspiration, and calibrating the depth and format of the case to the nature of the organisation and the significance of the decision.
A business case should be the best possible argument for a decision, constructed with honesty. It should be willing to surface the conditions under which the proposed initiative might not succeed, and it should give the decision-maker everything they need to commit with confidence or to decline with clarity. That standard is achievable at any scale. It simply requires knowing what questions to ask, and being honest enough to answer them.