--- title: "Scenarios & assumptions glossary" url: "https://help.sherloc.elementaryb.com/en/article/scenarios-assumptions-glossary" language: "en" last_updated: "2026-10-05T21:41:30.443Z" --- # Scenarios & assumptions glossary Plain-English definitions for the terms and options you'll see while building an assumption in sherloc, in the order you'll meet them, from starting an assumption through to reading the result. ## Scenario vs. Assumption **Forecast scenario** A forecast scenario is a forecast you've duplicated, which is a safe place to experiment. It's made up of your accounting figures and your business data, with assumptions over both, and anything you change inside it applies only to that forecast, so your core data stays as it is. **Assumption** An assumption is a change you make within a forecast, which is the specific change you're applying to one or more line items. A forecast can hold one or more assumptions. You'll see both words in the product: the button reads "Create assumption" and the panel that opens is titled "Create Assumption". These are the same action. Forecast scenarios are the forecasts you duplicate from the Forecasts page; assumptions are the changes you make inside them. ## Actuals vs. Forecast **Actuals** Your actuals are the real, historical figures already recorded in your accounts: the numbers that have actually happened. **Forecast** Your forecast is what continues after your last actual month. Where there's no assumption on an item, sherloc repeats your last closed month in every month ahead. ## How building an assumption works Select **Create assumption** and a step-by-step side drawer, titled **Create Assumption**, opens. It has three steps, and each one shows a short summary of what you've chosen once it's complete. ### 1\. About the assumption & where to apply it Give your assumption a name, then choose the sheet it applies to from the **Select the sheet impacted by the assumption** dropdown: for example Profit And Loss, Balance Sheet, Revenue, Equity or Staff. Next, tick the row items it affects from the checklist; each one appears as a removable chip. The name is required, and there's an optional notes field too. The sheets listed come from your own forecast, and changing the sheet clears the row items you've ticked. ### 2\. When should the assumption happen Choose which months the assumption affects, using one of three options: - **All months**: applies to every month of the forecast. There's no From month to pick. - **Date range**: pick a From and a To month; the assumption applies across that range. - **Specific months**: type to find and select individual months one at a time, each shown as a removable chip. ### 3\. What the assumption is modelling This step opens with an **Assumption applies to** card showing the items and months you've chosen. Below it, choose how the change should be calculated from four cards (see Change types below) and enter the amount. Once you've chosen a change type, an **In plain terms** line explains in plain English what the assumption will do. Select **Add assumption** to finish. After you choose a card, the list collapses to that card, with a Change button if you'd like to pick a different one. ## Change types The four ways a change can be calculated. ### Replace the figure Overwrites each month with a value you choose: every month it applies to takes on that same figure, regardless of what was there before. You can enter the figure yourself (**A number I enter**) or base it on a figure already in your data (**Another figure in my data**), in which case it updates automatically if that figure changes. **Logic:** New value = the £ amount you enter in *What figure should it become?* (replaces whatever was there). With *Another figure in my data*, you pick the sheet, a line item or a category, and the value to use. **Example:** You set a figure of £5,000 for March, April and May. Each of those three months now shows exactly £5,000, replacing whatever was there previously. **Example:** You base a cost line on a Business Data category totalling £4,000. That line shows £4,000 each month the assumption applies, and updates automatically if the business data total changes. ### Set to a percentage of a line item Each month becomes another line item's figure for that month, multiplied by a percentage you choose. It moves whenever that line item moves. **Logic:** Each month = that month's figure for the line item you pick × the percentage you enter. You choose *Which sheet?*, *Which line item?*, *Which value?* and *What percentage of…?* **Example:** You set Cost of Goods Sold to 30% of a sales line. In a month where that sales line is £10,000, Cost of Goods Sold is £3,000; in a month where it's £12,000, it's £3,600. ### Increase / decrease Adds to or subtracts from the current figure, applied independently to each month you select rather than building on the month before. You can use a **£ Fixed amount** or a **% Percentage**, entered in *How much?*, and a negative number makes it a decrease. **Logic:** Each selected month = that month's own current value ± the £ or % you enter **Example:** March, April and May are each currently £3,000. You apply an increase of £500. Each of those three months becomes £3,500, independently, not building on each other. ### Consecutive monthly change A cumulative change that increases or decreases every month: each month builds on the last, so the change compounds over time. Under **Change by** choose **£ Fixed amount** or **% Percentage**, then enter it in *Change each month*. It's only available when the months you've chosen are at least two in a row, such as All months or a date range. **Logic:** The change starts in the first month you select. Each month = previous month ± the £ or % you enter (rolls forward every month until the period ends, then the figure returns to its base) **Example:** February, March and April are each £1,000. You apply a consecutive monthly change of +£200, starting in February. February becomes £1,200, March becomes £1,400 and April becomes £1,600, each month building on the last. ## Reading an assumption once it's created These appear on your forecast when you choose **Accounts & Assumption Details** (see below). ### Base row The line's figure before the assumption is applied. ### Assumption row A highlighted row named after your assumption, with an Edit button so you can change it. A blue dot also appears beside the line's name so you can see at a glance which lines have an assumption on them. ### Result row The final figure for each month once the assumption has been applied. ### Formula icon (fx) on the Result row Shows the calculation behind the result itself. It is separate from the assumption's own explanation; this is about how the final number was worked out. ### Help icon beside an assumption's name Hovering over it may show a plain-English description of what the assumption does. ## Three ways to view assumptions A set of three icon buttons above your forecast table switches between them; hover over each icon to see its name. ### Accounts The default view: your sheet as normal, without the assumption rows. ### Accounts & Assumption Details Shows your full sheet with the rows behind each assumption (Base, the assumption itself and Result) beneath each line it applies to. ### Assumptions Only A filtered view that lists just the assumptions applied to that sheet, without the rest of the forecast around them.