🧰 Before You Begin: What You Need Ready
A credible baseline needs more than “last year’s numbers.” First, confirm the decision scope: what options you’re comparing, over what timeframe, and from whose perspective (group, business unit, customer segment). Second, gather the minimum operational and financial inputs that represent “today”: volumes, pricing, staffing levels, service levels, backlog, churn (if relevant), unit costs, and any known contractual changes already committed. Third, list the “inevitable changes” that occur even if you do nothing: wage inflation, supplier indexation, planned maintenance, customer growth/decline trends, regulatory changes, and system renewals that are already funded. Most baseline failures come from missing these inevitabilities-then options look artificially good because the baseline was frozen in time. Use a structured business case template so your baseline assumptions are captured in plain English, not hidden in cells. If you’re modelling in parallel, decide where the baseline lives (one model, one owner) and how changes will be approved-Model Reef’s workflow approach makes it easier to keep a single baseline scenario that every option references consistently.
🧩 Step-by-step implementation
Step 1: 🔒 Define “do nothing” precisely (scope, boundaries, timing)
Write a one-paragraph definition of “do nothing” for your business case. It should include: what continues as-is, what must still happen to keep the lights on, and what is explicitly excluded. For example: “We continue operating with the current platform; we still renew mandatory licenses; we maintain current service levels; we accept expected wage inflation; we do not add automation or new headcount beyond existing hiring plans.” This turns baseline debates into a documented scope conversation instead of an emotional argument. Then align the baseline to your business case strategy: if the strategy is risk reduction, your baseline must include the risk trajectory of doing nothing (e.g., failure rates increasing, compliance exposure rising). This framing makes your later business case justification cleaner because the baseline is not a strawman.
Step 2: 📊 Build the baseline forecast (run-rate + inevitable changes)
Start with a run-rate view that matches reality: last 3-6 months annualised (or seasonally adjusted if needed). Then layer in “inevitable changes”: wage inflation, supplier indexation, contract renewals, known churn, and committed capex/opex. If your environment has growth trends, include them-but keep them defensible (use internal historical patterns first). The baseline should not be optimistic or pessimistic; it should be plausible. This is the foundation for your business case analysis, because every option’s “incremental benefit” is measured against this baseline trajectory, not a flat line. A practical technique is to separate baseline assumptions into “certain” (contractual) versus “estimated” (trend-based), and then keep the estimated ones conservative. If you’re using Model Reef, encode these as baseline drivers so updates are controlled and consistent rather than patched into multiple spreadsheets.
Step 3: 🔁 Design the comparison logic (incremental deltas only)
Now define how options will be compared. The simplest rule is: option value = option forecast – baseline forecast, line by line, period by period. This forces you to focus on incremental impact, which is what decision-makers actually fund. It also prevents common manipulation like counting “total future revenue” as an option benefit when much of it would have occurred anyway. Create a benefits and costs mapping that explicitly shows which lines are incremental and why. Then align your comparison tables to the headings reviewers use in business case evaluation (benefits, costs, risks, dependencies, timing, and sensitivity). When this structure matches evaluation logic,your committee conversations become faster and more objective. If you’re running multiple options, keep the baseline locked and only flex the deltas-so options don’t accidentally carry different baselines.
Step 4: ✅ Validate baseline assumptions (and stress-test credibility)
Baseline credibility comes from stakeholder validation. Run a short review with operational leaders and finance: “If we did nothing, would this baseline path occur?” Ask them to identify only the top three baseline assumptions that matter most. Then stress-test those assumptions with a simple downside/upside range (e.g., demand -5% / +5%, wage inflation +1%, churn +2 points). You’re not trying to build a full scenario universe-you’re proving the baseline isn’t fragile. This is also where scenario discipline matters: if one baseline assumption dominates the outcome, you need to elevate it as a decision risk. A structured scenario approach helps you keep comparisons honest and updateable over time. In Model Reef, baseline validation is easier when you can show the baseline driver set and the resulting outputs in one view, instead of defending disconnected spreadsheet tabs.
Step 5: 📋 Publish the baseline as a governed artefact (reusable and stable)
Once validated, treat the baseline as a governed artefact. Give it an owner, a version label, and a refresh cadence (monthly or quarterly, depending on decision velocity). Document baseline logic in plain English inside your business case report, including what is included, what is excluded, and why. Then publish the baseline outputs in a format that reviewers can consume quickly: trend charts, totals by year/quarter, and a concise assumptions page. When you can generate consistent outputs without manual reformatting, baseline discussions stop being spreadsheet debates and become decision discussions. If you use Model Reef, you can centralise baseline assumptions, keep versions clean, and export committee-friendly views using reporting outputs instead of rebuilding the story each time.
🧪 Example / Quick Illustration
You’re assessing whether to implement a new collections process. A weak baseline says: “AR stays the same.” A credible “do nothing” baseline says: “AR days trend up by 2 days over 12 months because invoice volume is rising faster than collections capacity; wage inflation increases collections cost by 4%; and existing customer payment terms remain unchanged.” When you compare the new process option, you only count incremental changes: AR days improve versus the baseline trend, not versus today’s static AR days. This mirrors how good budget-to-actuals logic works: you track what moved, why, and whether the movement was preventable. If you want a clean way to show the baseline-to-option cash bridge, use a structured cash-variance style narrative rather than a wall of numbers.
🚀 Next Steps
With a governed “do nothing” baseline in place, every option comparison becomes faster, cleaner, and more credible-because you’re debating deltas, not debating reality. The next move is to standardise how you store baseline assumptions, how you refresh them, and how you publish comparisons for stakeholders. Model Reef can help by keeping baseline drivers and option deltas in one place, generating consistent outputs, and reducing the spreadsheet sprawl that often undermines business casing at scale.
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