Warehouse Workflow Lab

Compare two workflow methods fairly

Published by Voodoo Robotics · workflows.voodoorobotics.com

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Comparison design

What to do: Define A, B, and allocation.

Method ADescribe the current method.Example: One order at a time with handheld scannerMethod BDescribe the proposed method.Example: Eight orders on one guided cartRandomization / matchingExplain how workers and orders will be assigned fairly.Example: Match both methods by order-size group and workerCrossover planState when the same workers will switch methods.Example: Switch every two hoursWorker assignmentName the role or person and shift when it matters.Example: Day-shift picker; 6 months experienceWarm-up excludedState practice time that will not count in the results.Example: First 20 minutes after each switch

Stratification

What to do: Keep order size and mix from deciding the answer.

Lines/order bandsDefine the order-size groups used to keep both methods comparable.Example: 1 line, 2–5 lines, and 6+ lines per orderItem cube / weightDefine product size and weight groups that must be balanced between methods.Example: Under 1 L, 1–10 L, and over 10 L; under and over 10 lbZone / routeUse the real warehouse name or location code.Example: Zone A, locations A-01 through A-48Priority / cutoffList service priorities or shipping cutoffs that must be represented equally in both methods.Example: Same-day orders due by 4 p.m. and ordinary next-day ordersException riskDescribe what went wrong, where it was noticed, and the practical effect.Example: Wrong product scanned; tote moved to EXC-01Worker experienceName the role or person and shift when it matters.Example: Day-shift picker; 6 months experience

Measures

What to do: Use identical definitions.

Primary responseName the main result that will be compared between Method A and Method B.Example: Completed order lines per direct labor-hourAccuracy measureUse a count divided by a clearly named opportunity and include the time period.Example: 8 per 1,000 lines = 0.8%Training / usabilityState how training effort and ease of use will be measured for both methods.Example: Minutes to independent work and worker rating after 40 ordersException recoveryState how recovery from a defined problem will be measured.Example: Minutes from SHORT selection until the tote returns to normal flowConfidence / uncertaintyState how certain the comparison is and what range or sample limitation remains.Example: Method B was 8–12% faster across 400 matched ordersSample requirementEnter a measured count and the period or group it covers.Example: 1,200 order lines during the day shift

Confounders

What to do: Record events that could bias results.

Replenishment disruptionRecord refill delays or stockouts that affected either comparison method.Example: Method B lost 24 minutes to two late refillsSystem latencyUse a number and unit, and state the start and stop points when needed.Example: 42 secondsEquipment failureDescribe what went wrong, where it was noticed, and the practical effect.Example: Wrong product scanned; tote moved to EXC-01Staffing differenceRecord differences in headcount, experience, breaks, or supervision between methods.Example: Method A included one trainee; Method B used four experienced pickersDemand anomalyRecord unusual order volume or mix that could distort the comparison.Example: A promotion doubled single-line orders during the Method B blockLayout changeRecord any product, station, aisle, or route change made during the comparison.Example: Printer moved 30 feet closer before the second Method A block