Strategic Planning Assumptions: How Leadership Teams Test Them Before 2027

3 min read

Every annual plan is a set of strategic planning assumptions dressed up as targets.

Revenue will grow because customers will keep buying the way they did last year. Margins will hold because costs will stay predictable. The leadership team will deliver because the people in key roles are ready for what's coming.

Most strategic planning assumptions were reasonable when the plan was drafted. The risk is that some of them will quietly stop being true while the plan is still running.

By the time the gap shows up in quarterly results, the cheapest moment to adjust has already passed.

Why Strategic Planning Assumptions Fail Quietly

Plans rarely fail because leaders made a careless forecast. They fail because an assumption that was true in October stops being true by May, and no one was assigned to notice.

Planning cycles reward commitment. Once a number is agreed, questioning the assumption underneath it can feel like disloyalty or weakness. So the assumption becomes a fact, and the fact goes unchecked.

Find the Strategic Planning Assumptions That Carry the Most Weight

Not every assumption deserves the same attention. RAND's Assumption-Based Planning method gives leadership teams a useful filter. Look for assumptions that are:

Load-bearing: If this assumption is wrong, the plan needs significant change.

Vulnerable: Plausible events in the next 12–18 months could make this assumption wrong.

The assumptions that are both deserve a leadership conversation now, not at the mid-year review.

One practical way to find them: read your plan and highlight every sentence that says something will happen. Each "will" is a hidden assumption (Project Management South Africa review of Dewar).

Five Places Expired Assumptions Hide

1. Customers

Are we assuming customers will buy, decide, and stay loyal the way they did when this strategy was built?

2. Markets and geography

Are we assuming that what works at headquarters, or in our largest market, will work the same way everywhere? This is where Global Mindset matters. An assumption that holds in Seoul, Frankfurt, or Chicago may not hold in Jakarta or São Paulo.

3. Talent

Are we assuming the people who delivered 2026 are ready to lead 2027? Plans often assume leadership capacity that hasn't been tested yet.

4. Technology

Are we assuming AI and automation will change our competitors' work faster than ours, or later than they actually will?

5. Leadership habits

Are we assuming the decision speed, escalation patterns, and meeting rhythms that worked this year will be fast enough next year?

Turn Strategic Planning Assumptions Into Signposts

Testing an assumption once in November isn't enough. For each critical assumption, agree on a signpost: an observable signal that would tell you it's weakening.

AssumptionSignpostWho watches it
Our top three customers will renew at current volumeA change in who attends renewal discussions, or slower decision cyclesCommercial lead
Our regional leader is ready for expanded scopeDecisions keep escalating to HQ after 90 daysCHRO and CEO
Our cost base will stay stableSupplier lead times or pricing shift two quarters in a rowCOO

Then agree in advance what you'll do if the signpost appears. That turns a surprise into a decision you've already rehearsed.

Questions for Your Next Leadership Meeting

  1. Which three assumptions in our 2027 plan would cause the most damage if they turned out to be wrong?
  2. Which of those assumptions have we not checked since we first agreed on them?
  3. Which leaders are we counting on to take on a bigger scope, and how have we tested whether they are ready?
  4. For each critical assumption, what early signal would tell us it is weakening, and who is responsible for watching it?
  5. If that signal appears, what have we already agreed to do?
  6. Does everyone on this team feel free to question an assumption without it being seen as disloyal?

Build a Plan That Can Learn

The goal isn't a perfect forecast. It's a leadership team that knows what its plan depends on, watches the right signals, and acts before the results force it to.

McKinney Consulting works with leadership teams and senior executives to stress-test plans, strengthen decision-making, and prepare leaders for the conditions ahead. For a Q1 kickoff or planning offsite, Steve McKinney's Proactive Agility keynote and workshop gives the whole team a shared way to do this work.

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Posted on November 9, 2026
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