Scenarios vs projects
When to use a scenario and when to use a project in bluprnts — one bends your whole plan's assumptions, the other adds a self-contained initiative.
Both live under What-if and both answer "what if?", but they work in opposite directions. A scenario bends the assumptions around the plan you already have. A project adds something to the plan that wasn't there — with its own products, sales, people, costs and financing — which you then switch on and off.
The quick test: if you'd have to invent new line items to model it, it's a project. If you'd only have to change the numbers on existing ones, it's a scenario.
The difference#
| Scenario | Project | |
|---|---|---|
| What it is | A set of adjustments applied over the plan | A layer of real drivers added to the plan |
| What you enter | Levers — percentages, days, a funding amount | Products, sales, employees, costs, financing |
| Scope | The whole business at once, or a targeted slice of it | One initiative |
| How you switch it | Applied app-wide, one at a time | Toggled on or off, independently, any number at once |
| Compared how | Side by side in Compare | By its own contribution, on and off |
When to use a scenario#
When the shape of the business is right but the numbers might not be:
- Sales come in 20% under plan
- Everyone's costs rise 8% next year
- A key customer starts paying 45 days late
- You freeze hiring for six months
- You raise £500k
None of these need anything new in the model. They are your existing drivers, moved.
When to use a project#
When you're adding a distinct piece of business that has to be built before it can be judged:
- Launching a new product line
- Opening a second site
- Entering a new market
- Taking on a big fixed-term contract
Each brings its own revenue and its own costs, on its own dates. You need somewhere to put them, and you need to see the business with and without them — that's a project.
They stack#
A project that is switched on is part of the plan, so a scenario acts on it like anything else. Model the new site as a project, switch it on, then apply a "volume 20% under plan" scenario to ask the more useful question: not "does the new site work?" but "does the new site still work if we're wrong about demand?"
That layering is the point. Base is what you've committed to, projects are what you're considering adding, and scenarios are how confident you are about any of it.
Related#
- What scenarios are — the levers and what they bend.
- Add or edit a project — build one.
- Base, projects and scenarios — how the three layers combine in the engine.