What it means
A picker reaches an empty forward location even though reserve stock exists elsewhere in the warehouse. A replenishment rule should have triggered a move early enough.
Trigger accuracy checks whether those signals fire at useful times and quantities. Define the movement, because Oracle describes replenishment from reserve locations to picking locations to meet demand, with modes based on minimum capacity, volume percentage, manual scans or orders, and the appropriate trigger depends on operation design.
Choose the event to predict, since the rule may aim to prevent pick-face stockouts before the next wave, maintain a minimum quantity or meet known orders, and the goal should be stated before judging accuracy. Record the trigger and result by capturing, for each SKU-location, level, time, replenishment task, completion and later demand, because a trigger alone is not a completed stock move.
Measure false negatives, where a location needed replenishment but no task fired before a pick failure or defined threshold, and check whether stock records or rule settings were wrong. Measure false positives, where a task fired when stock was already sufficient under the goal and added needless travel, although some early replenishment can still be sensible before peak demand.
An illustrative precision is 90 useful replenishment tasks out of 100 triggered tasks, or 90%, while recall is separate: if 120 locations truly needed moves and only 90 were covered, recall is 75%. Define useful objectively, because a task might be counted useful if it prevented a forecast pick shortage within a stated horizon and should not be labelled useful merely because a worker completed it.
Watch data freshness, since if scans arrive late the system may think a bin has more stock than it does, so inventory accuracy and trigger logic are linked. Check reserve stock, because a rule can fire correctly but fail because no usable reserve stock exists, and report supply shortages separately from trigger misses.
Account for task lead time, since a move requiring 30 minutes cannot help an order wave starting in five minutes and trigger settings need enough buffer. Consider order pattern and item class, as a SKU with steady daily demand differs from a promotional item with a sharp peak, fast movers can need frequent replenishment while slow movers may use different pick locations, and one threshold for every SKU can perform poorly.
Check physical capacity and unit conversions, because replenishing to a calculated maximum may overfill a bin or create unsafe stacking, and cases in reserve against pieces in the pick face need consistent quantities or tasks can fire too early or too late. Avoid duplicate tasks, since two triggers for the same location can send workers twice unless the system recognises an open move, and review cancellations by reason because a task may be cancelled when the order was cancelled or the stock was moved manually.
Distinguish accuracy from speed, as a correct trigger that waits in a queue still leads to a stockout, and review untriggered needs by looking at picks missed because a bin was empty, since sampling only completed tasks cannot reveal false negatives. Test changes in a pilot and keep exception notes for blocked aisles or missing pallets, report sample size and period because 90% precision on ten tasks is more uncertain than the same rate on thousands, and remember that the best rule fires in time, for the right stock, without overwhelming the team with wasted moves.
In practice
Real-world examples.
Example
A fast-moving bin receives a move request before the next order wave, and the pallet arrives with 20 minutes to spare. Pickers find the face stocked and no pick fails.
Example
A false alert sends a worker to a pick face already sufficiently stocked. The move adds travel without protecting any order, and it is counted as a false positive.
Example
A missed trigger is found by reviewing empty-bin pick failures. The team backtracks to the rule, finds a stale threshold for that item and logs the miss as a false negative.
Formula
Calculation
Illustrative precision = useful triggered tasks / all triggered tasks x 100. Illustrative recall = genuine needs covered by a timely trigger / all genuine needs x 100. State the useful-task rule and the time horizon.
Worked example. A site triggers 100 replenishment tasks in a week, and 90 of them prevented a forecast pick shortage within the stated horizon. Precision = 90 / 100 x 100 = 90%, and the other 10 tasks were false positives.
Separately, 120 pick locations genuinely needed a move and 90 of them were covered by a timely trigger. Recall = 90 / 120 x 100 = 75%, so 30 needs were missed (120 - 90 = 30) and should be reviewed for stock-record or rule-setting errors.Case study
Seen in the real world.
This entirely fictional example follows Maple Warehouse. Its pickers found empty bins despite reserve stock, while other aisles had duplicate replenishment tasks. The team compared trigger logs, open tasks and later order waves. Maple adjusted one fast-mover threshold and duplicate-task handling, then watched both missed picks and labour. The example does not claim a universal target for precision or recall.
Watch out
Common mistakes.
- Measuring only completed moves and missing untriggered shortages.
- Treating a valid trigger as proof a stock move happened on time.
- Lowering stockouts by firing so many tasks that labour and congestion rise sharply.
Questions
People also ask.
What is a useful trigger?
One meeting the stated need and timing rule for a pick location.
Why measure missed needs?
Task-only reports cannot show cases where no alert fired.
What else affects results?
Stock accuracy, reserve availability, task lead time and picker demand.
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