Scenarios

A scenario is a named case built on top of the base case. It does not copy the process. It stores only the inputs it changes, as an ordered list of changes. Each change is a variable path and a value, for example economics/tax_rate = 0.25. The base case is always the document: it is what you save, what Undo steps through and what the title-bar “•” refers to. Scenarios are saved in the same .flow file.

Open the workspace with Tasks ▸ Scenarios…, the Scenarios button on the Economics tab or in its toolbar group, or the Scenarios node of the Model tree. Ctrl+K finds every scenario command (“scenario …”).

Creating scenarios

• + New adds an empty scenario. Use ✎ Edit to fill it (see below), or type a variable path under the change list and click + change.

• What-if chips create a scenario from a short phrase, without AI:

  Phrase	Changes
  titer ×2	final-concentration targets of reactions (otherwise reaction extents, capped at 1)
  yield ×1.2, conversion +5 %	reaction extents (capped at 1)
  price +10 %	selling prices: revenue-stream prices and component selling prices
  raw materials −20 %	component purchase prices
  batch size ×2	the amounts of every process feed
  labor +15 %, electricity +25 %, steam +30 %	labor rate, power price, heat-transfer agent costs
  tax rate = 25 %, discount rate = 10 %, operating hours −10 %, project life = 20	the matching economic setting
  economics/tax_rate = 0.3	any variable path

  The change is × or x (multiply), / (divide), + % or − % (relative), + or − (absolute) or = (set; = 25 % sets 0.25). Type your own phrase next to the chips and click Create.

• Proposed changes: edits proposed by an AI agent (MCP) or the automation API can be kept as a scenario instead of being applied (Tools ▸ Save proposed changes as a scenario, or the button in the workspace). The base case is not changed.

• Study sample: pick a study that has been run and a sample number. The new scenario sets every study parameter to that sample’s value.

• ⧉ Duplicate copies the selected scenario.

Editing in a scenario

Click ✎ Edit next to a scenario (or Edit in scenario in its context menu). A coloured banner under the toolbar shows the scenario being edited and how many changes it has. The whole application now shows the scenario’s case: the flowsheet, every tab, the Settings pane and the results. Any edit you make, in any window, is recorded as a change of the scenario. The base case is not touched.

• In the Settings pane, the fields of the selection that the scenario changes are listed with the scenario value and the base value next to it, struck through. Click ↺ to revert that field to the base value. The base value also appears in the Equations symbol list.
• Setting a field back to its base value removes its change.
• Undo and Redo work as usual. Each edit is one step.
• Adding or removing procedures, streams, operations or other items is not recorded in a scenario. To change the flowsheet structure, click Edit base case in the banner first.
• Moving units on the flowsheet, renaming the process and display settings are not scenario changes. They go to the base document.

Click Edit base case in the banner, or Edit base case in the workspace, to leave the scenario. Entering or leaving a scenario does not change the document.

Run all and compare

▶ Run all solves the base case and every scenario on background threads. Each case is a full re-simulation. The comparison table lists, for every case:

• unit production cost, cycle time, batches per year, main-product output;
• NPV, IRR and minimum selling price (when cost evaluation is on);
• process mass intensity, CO₂e (when CO₂-eq factors are set);
• the number of errors and warnings.

Below each scenario value are the change from the base and the change in percent, in green when it is an improvement. A note appears when the process or the scenarios have changed since the last run.

Waterfall

The waterfall explains how one key figure moves from the base case to a scenario. Pick the key figure and the scenario and click ▶ Compute. The changes are applied one at a time, in the scenario’s order. Each bar is what that change adds, given the changes before it. The first bar is the base case and the last bar is the scenario; the steps always add up to the difference.

When changes interact, the split between them depends on the order (path dependence). For example, a higher titer is worth more at a higher selling price. Reorder the changes with ⏶ ⏷ to see another split.

Promote, delete, reorder

• ⬆ Promote to base applies the selected scenario’s changes to the base case and removes the scenario. It is one undo step. The other scenarios keep their changes and now build on the new base.
• ✕ Delete removes a scenario (undo brings it back).
• ⏶ ⏷ next to a scenario changes its position in the list and in tables.

Exports and reports

• ⤓ CSV and ⤓ Excel (also File ▸ Export scenario comparison… in Ctrl+K) write the comparison table. The Excel workbook has a second sheet, “Deltas”, with every changed input and its base value.
• HTML and Word reports of a process with scenarios include a Scenarios section with the comparison and the list of changed inputs.

Older files

Earlier versions kept “named variable overrides” under the economics studies (economics/ext/scenarios). Those files still open. Their scenarios appear in the workspace with the same changes, and are saved in the new place from then on. The tornado and throughput scale-up studies are now under Tasks ▸ Tornado & scale-up….

Variable paths are the ones used by flowstate-cli get/set and the automation API; see Command line and automation API.