Time And Motion Study
A time and motion study is a structured industrial engineering method that measures task duration and evaluates worker movements to identify waste, set engineered labor standards, and improve process efficiency. It combines time study and motion study, converting observed work into measurable data for benchmarking, labor planning, and process redesign in manufacturing, warehousing, and supply chain operations.
On the shop floor, a time and motion study begins with a repetitive task like pallet receiving, line-side replenishment, or order picking. Analysts break that task into discrete elements such as scan, lift, transport, stage, verify, and release, then record actual cycle times across multiple cycles using stopwatches, video, or software. The observed times are adjusted for performance rating and allowances to produce a standard time. In a warehouse, this data drives decisions like re-slotting fast-moving items closer to the pick face, reducing backtracking, and rebalancing labor between inbound and outbound operations. In raw material tracking, the study exposes time lost in kitting, material issue transactions, forklift waiting, or locating pallets. These delays directly affect line starvation and inventory accuracy. The final output is usually a documented standard method or process redesign recommendation, which is then measured against KPIs such as dock-to-stock time, pick rate, travel distance, or units per labor hour.
- Receiving bottleneck from hidden motion waste: Inbound pallets arrive on time, but operators waste minutes searching for staging locations or reworking labels, causing dock doors to back up and trailers to dwell while the real constraint remains invisible in top-line cycle-time reports.
- Stockout at the line despite full inventory: Material exists in the warehouse, but time losses in putaway, replenishment, or kitting delay release to production. Inventory availability becomes constrained by movement and staging time, not by quantity, leading to line starvation and expediting.
- Bad labor standards from unrepresentative sampling: A standard built from too few observations or atypical operators creates unfair quotas and chronic overtime. If rating, allowances, and cycle variability are mishandled, the resulting standard time fails to reflect actual repeatable performance.
What is the difference between time study and motion study?
A time study measures how long each task element takes, while a motion study evaluates the physical movements used to perform the task and removes unnecessary motions. Together they establish the most efficient method and a defendable standard time.
What outputs does a warehouse engineer expect from a time and motion study?
Expected outputs include standard time, a process map, a labor benchmark, travel-distance reduction opportunities, and a prioritized list of workflow improvements. These outputs directly support slotting changes, labor rebalancing, and throughput improvement initiatives.
What metric problem does it solve in supply chain operations?
It converts 'we feel busy' into measurable labor content, showing whether delays come from travel, waiting, excessive handling, poor slotting, or non-value-added approvals. This visibility enables targeted improvements instead of relying on intuition or top-line cycle times alone.