Reducing transfer batches from 100 to 20 units requires a completion-time calculation and a test of the extra handling work. This Lean Six Sigma example uses published processing data to calculate the effect of smaller transfers. The pilot then tests whether the predicted time saving holds under production conditions.
Asiantuntijoille, jotka noudattavat Lean Six Sigma Internationalin Sertifiointiohjelmat, the decision is specific: does releasing completed units earlier justify changing the handover rule?
Transfer batches and production runs
A production run can remain intact while completed portions move downstream. Research published in the European Journal of Operational Research in 2026 distinguishes consecutive processing of these smaller portions from arrangements that interrupt or distribute them. Those arrangements can introduce additional setups. A Lean Six Sigma analysis therefore needs to state the setup assumptions alongside the transfer quantity (sciencedirect.com).
The proposal here retains the 100-unit production run and transfers completed groups of 20. The arvovirtakarttaan should show the release condition between operations. Changing the production-run size would require a separate setup analysis; SMED would apply if that analysis identified a need to reduce changeover time.
Calculate completion time with 100-unit and 20-unit transfers
Ramasesh and colleagues’ paper, published in 2000, provides the inputs for this calculation. The order contains 100 units. Processing times are 2, 3 and 4 minutes per unit, with setup times of 50, 75 and 75 minutes, respectively. The Lean Six Sigma calculation below extends the published example to 20-unit transfers (sciencedirect.com).
The model allows one setup per machine, beginning when its first batch arrives. Transport takes no time. There are no breakdowns, and no other work competes for the machines. Each completed sub-batch moves immediately.
Baseline: 50 + 200 + 75 + 300 + 75 + 400 = 1,100 minutes.
With 20-unit transfers, the first batch finishes after 50 + 40 + 75 + 60 + 75 + 80 = 380 minutes. The remaining four batches finish 80 minutes apart: 380 + (4 × 80) = 700 minutes.
The calculated reduction is (1,100, 700) ÷ 1,100 = 36.4%. That figure comes from extending the published model; factory savings remain to be measured (sciencedirect.com).
| Completion measure | 100-unit transfers | 20-unit transfers |
|---|---|---|
| First complete transfer batch | 1,100 minutes | 380 minutes |
| Entire order | 1,100 minutes | 700 minutes |
Earlier completion does not establish a capacity increase
The 36.4% reduction concerns elapsed order time. Each machine still performs the same amount of processing per unit; the transfer rule changes when downstream work begins. Lot streaming allows successive machines to work on different portions of the order at the same time, accounting for the shorter completion time in this model (pure.psu.edu).
For the projektin perustamisasiakirja, elapsed time from the start of the first setup to completion of the final conforming unit provides a clear primary measure. It keeps completion of the first 20-unit transfer batch separate from completion of the order. If the customer benefits from receiving a partial quantity early, that timing warrants a separate measure.
Handling needs its own measurement. Research published online in 2024 examines production scheduling together with transport resources because omitting handling time leaves the scheduling model incomplete (tandfonline.com). The Lean Six Sigma pilot therefore needs records of collection delays and transport workload to test the assumption of immediate movement.
DMAIC pilot: test the release rule under operating conditions
Laitteessa DMAIC, the calculated reduction provides a hypothesis for the Improve phase. The pilottitestin needs to isolate the transfer rule. Concurrent changes to staffing or inspection requirements would make it difficult to attribute a change in completion time to smaller transfers.
The measurement plan for the 20-unit trial should include:
- Order completion time: use the same entry and exit events for the baseline and trial.
- Good output and quality: retain the existing acceptance requirements and track ensi läpäisyn saantoa.
- Handling workload: record transfer frequency and labour time. Log collection delays separately.
- Queue location: observe whether completed sub-batches accumulate before the next operation.
Before the trial, the Process Ownerin and sponsor need to agree on the evidence required to retain the 20-unit rule. Acceptance criteria should cover delivery performance and a quality tasapainottavana mittarina. The pilot’s measured completion time can then be compared with the model’s prediction.
Put the 20-unit release rule into the control plan
If the trial meets its acceptance criteria, the ohjaussuunnitelman should assign responsibility for releasing each completed 20-unit group and specify how lot identity is preserved. It also needs a response for occasions when downstream processing cannot accept a group. The associated standardityö should define how to handle incomplete final groups and units awaiting quality disposition.
NIST identifies time plots and ohjauskortit as tools for assessing process stability (itl.nist.gov). After implementation, the Lean Six Sigma project’s control review should use time-ordered data to establish whether the shorter completion times persist across operating conditions. Responsibility for responding to handling delays or quality losses belongs in that review.
Lean Six Sigma Internationalin Sertifiointiohjelmat cover process-flow analysis and DMAIC problem solving. The progression also includes statistical process control under the LSSx.0 standard (leansixsigma.org). The appropriate level depends on the participant’s responsibility for analysing the pilot and validating its results.
