Distribution Center Wastes Before Automation
At a regional distribution center, 1,800 orders per day are picked, packed, and shipped across three shifts. Pickers walk an average of 9.5 miles per shift; travel is estimated at 42% of picking time. The pick-to-light system is only used in two of six aisles. Mispicks run at 1.8% of orders, and 6% of orders are held because packaging materials are stored 150 meters from the pack benches. The DC manager wants to buy an automated conveyor and sortation system costing $2.1 million. The finance director asks for a lean assessment first. A recent employee survey shows that pickers have submitted only four suggestions in six months, and supervisors say they are too busy to run improvement meetings. Space is constrained; adding conveyor would remove two staging lanes.
1. Classify the main wastes in this DC and rank them by likely impact. What data would you collect before supporting or rejecting the conveyor?
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Main wastes: motion and transportation from 9.5 miles of walking and packaging 150 meters away; defects from 1.8% mispicks; waiting from 6% held orders; underused talent from only four suggestions; and underused pick-to-light in four aisles. Rank by impact using cost and customer risk: mispicks first (replacement, freight, customer penalty), then travel and walking (42% of picking time, labor capacity), then holds (late orders and expediting).
Before the conveyor, collect order profile by SKU velocity, pick density per aisle, travel path by zone, mispick root causes by picker, aisle, and shift, hold reasons, and packaging material usage by bench. Also calculate the labor hours and order cycle time that could be released by slotting and point-of-use packaging. The conveyor may be justified later for volume or ergonomics, but not as the first countermeasure.
2. Propose a 90-day improvement sequence that does not depend on the conveyor. How would you involve pickers and avoid shifting waste to another area?
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90 days: weeks 1-2 baseline and 5S in pick zones; weeks 3-4 slot fast movers near pack, move packaging to point of use, and expand pick-to-light to the highest-error aisles; weeks 5-8 standard work for pick-pack-ship, scan-based error-proofing, and a daily huddle with pickers; weeks 9-12 pilot one zone and measure end-to-end order cycle, mispicks, travel, and holds.
Involve pickers by asking them to map their own travel and test changes; recognize implemented suggestions, not just submissions. Avoid shifting waste: check that moving packaging does not block staging or increase replenishment trips, and measure pack and ship, not only pick rate. Use a before-and-after run chart to separate noise from improvement.