# The forecasting engine Source: https://docs.tightly.io/help/engines/forecasting Reviewed: 2026-09-24 ## What the forecasting engine is The forecasting engine says what each line is expected to sell, day by day, from what it has sold. It is four passes that can each be late on their own: the forecast itself, rebuilt with every sync; confidence, graded on every sync; the Monday accuracy pass at 06:30 UTC, which scores last week's forecast against what sold; and the Monday re-score at 06:45 UTC, which picks each line's method from its own history. Its page is [Demand forecasting](../demand/demand-planning), on every plan. ## When the forecast is built and refreshed The forecast is rebuilt after each sales sync; buying, stock-out dates and replenishment then use the new figures. In production, organisations active within thirty days sync hourly; inactive ones sync twice daily. A paused connection pauses its forecast. Recalculate now rebuilds the forecast from the sales already in Tightly, without pulling from your connected system again, and with the methods already chosen: it never re-runs the Monday re-score. The re-score and the accuracy pass run on their own each Monday and are not started from any page. ## How far ahead the forecast reaches The forecast reaches 58 weeks ahead, about thirteen calendar months, as a figure per day for each variant, location and channel. Demand forecasting adds those days into periods by the window you pick: a window of twelve days or less reads by day, under twelve weeks by week, and anything longer by month. A line's Forecast range, in its drawer, is the band its sales are expected to land inside about eight weeks in ten, drawn from how far the methods missed on your own past weeks. ## How the forecast is made for each line A line with enough history is forecast from its own sales by the method the Monday re-score chose for it. A line too short for a re-score keeps the method chosen for lines like it, still reading its own sales. A product that has never sold is forecast from analogs, past products that sold like it, on Essentials+ and Pro, which include Analogs. On Lite and Essentials none is proposed, so such a product has none to borrow and says so. - [Forecast methods and the Monday re-score](../engines/forecast-methods): which methods exist and how one is chosen. - [Forecast accuracy](../engines/forecast-accuracy): how the forecast is scored against what sold. - [Confidence as a word](../demand/confidence): how each line is graded. - [The forecast's words](../demand/forecast-words): what each chip on a line means. - [Manual forecast](../demand/change-the-forecast): typing your own figure over the system's. The forecasting engine is not the baseline engine. The baseline engine grades a style at one Tightly Connect account from that account's sell-out; the forecasting engine forecasts your own sales. ## What each plan sees of the forecast Forecast methods, confidence and accuracy are the same on every plan. Pro adds season and commitment scope and re-scores declared styles within their selling dates. The Analogs page is on Pro; other plans with analog entitlement use automatically chosen sources. ## The forecast's as-of and state sentences The head's as-of is the last forecast run, never your clock. Details holds the last sync. A run can be recomputing, late, stale or failed; Late begins four hours after the expected sync, Stale after twenty-six. Each state that needs you speaks one sentence, served by the engine and printed character for character: > The forecast has not run for this tenant yet. > Forecast as of {as_of}; a run was due {due}. > The last run rewrote {written} of {expected} lines; the rest are older. > Today's forecast run did not finish; figures are as of {as_of}. > No sales have synced yet, so there is nothing to forecast. > Forecasting is off for this tenant. > Paused with the connection; the forecast waits for the sync. > This tenant is not on the forecast run. On Demand forecasting that sentence is under Forecast status in the Forecast performance drawer. ## What you can do about the forecast Recalculate now stands beside the engine's sentence under Forecast status. A seat that can write may press it, once every two hours for your tenant, and it is refused while a run is already going. A paused forecast offers Integrations instead, because the sync is what stopped. To change a figure, type a Manual forecast on Demand forecasting. Ask Tightly can explain the forecast and prepare a change for exact variants, channels and dates. It saves only after you confirm, then provides the same scoped forecast to check. It cannot press Recalculate now for you. Nobody picks or pins a line's method: the Monday re-score decides it from your own sales. ## Saved assumptions A declared analog takes precedence over automatic sources for its channel and leaves the source product active. Other channels keep their own source. Check the result after recalculation; saving the mapping alone does not mean the forecast has refreshed. Borrowed evidence remains distinct from the new product's own measured history. A manual forecast adjustment belongs to its selected products, accounts or channels and dates. Clearing it restores the current calculated basis. Historical sales imports do not create forecasts that were never recorded; historical comparisons require recorded forecast vintages. A forecast change places no order. ## Glossary line What the forecasting engine expects each line to sell, rebuilt with every sync, with its basis word and its confidence word.