01 · Purpose and timing
Purpose and timing
Prepare Process Control means designing how an improved process will be operated, checked, and sustained before broad implementation. It includes standard work, measurement definitions, review cadence, ownership, evidence retention, and links to reaction actions. The purpose is to ensure the improvement survives ordinary variation, staff changes, equipment problems, and busy periods after the project team leaves.
Use it while the design and pilot are still being developed, not only after a successful launch. Prerequisites include a clear process boundary, the critical customer and operational requirements, and knowledge of the failure modes the new design introduces. Preparing control is broader than drawing a statistical control chart. Routine operational checks can be necessary even before sufficient stable data exist for valid statistical limits. Conversely, a dashboard alone does not provide control if nobody is authorized to respond.
02 · Choose what requires control
Choose what requires control
Fictional Northbank Dispatch introduces early carrier assignment and carton-to-lane confirmation. The team identifies four requirements: carrier identity must be correct, carton records must remain traceable, dispatch must meet collection timing, and recovery must work during an interruption. It selects a small set of checks tied to those requirements rather than measuring everything the software can export.
The leading check is whether a carton reaches staging with a valid assignment. The outcome check is the proportion of cartons loaded after the agreed carrier cutoff. A guardrail is wrong-carrier loading. Another guardrail is confirmation queue time. The process owner states the denominator and timestamp rules for each metric. A late carton is classified using the same cutoff definition on every shift. Missing timestamps are reported as missing, rather than silently treating those cartons as on time.
03 · Create an operational control plan
Create an operational control plan
For each critical point, Northbank specifies the requirement, method, frequency, responsible role, retained record, and response link. The assignment check occurs for every carton at release. The confirmation check occurs for every carton before loading. The shift lead reviews exception status at the start of the shift and before each collection wave. The process owner reviews performance daily during stabilization and weekly after acceptance.
Training covers the normal sequence and exception handling. Operators demonstrate the sequence with routine and reassigned cartons; attendance alone is not evidence of capability. The systems owner maintains configuration access and change records. The dispatch lead maintains the operating instructions. The control plan identifies who can stop release, who can authorize fallback, and who can restore normal operation. These roles make the measurements actionable and prevent a project dashboard from becoming a substitute for daily ownership.
04 · Worked measurement and review
Worked measurement and review
In a fictional ten-day stabilization record, Northbank handles 1,200 cartons daily. Across the 12,000 cartons, 180 arrive at staging without a valid assignment, giving 180/12,000 = 1.5%. Daily counts still matter because the same average can hide a bad collection wave or a shift-specific issue. The team stratifies by carrier and shift before declaring that the mechanism is stable.
The approved operating target is no more than 1% unassigned at staging, so the 1.5% result misses the target. This target is a requirement chosen for the process, not an upper statistical control limit. Northbank investigates the gap rather than inventing chart limits from a short, changing launch period. Once the process is stable and measurement is reliable, the team can choose an appropriate chart and establish limits from a justified baseline. Specification limits and statistical limits answer different questions and remain visibly separate.
05 · Handover and evidence of control
Handover and evidence of control
The project team transfers the map, approved standard work, configuration version, training evidence, metric definitions, and reaction plan to the dispatch owner. A handover review checks that the owner can obtain the data, interpret the checks, and authorize the response. Northbank runs a planned outage rehearsal and verifies that manifest reconciliation can detect duplicate or missing carton records before normal service resumes.
Control readiness is accepted only when the operating roles and recovery arrangements work in practice. The team retains open issues with owners and deadlines; a checklist marked complete does not erase an unresolved assignment failure. The first month includes scheduled observation on the night shift because training and system access differ from the day shift. The control arrangements are revised when they prove too burdensome, too late, or unable to distinguish a genuine failure from a data problem.
06 · Weak versus strong practice and advanced adaptation
Weak versus strong practice and advanced adaptation
Weak practice writes instructions after launch, monitors only a monthly average, treats a red dashboard cell as a reaction plan, or sets statistical limits equal to the customer target. Strong practice ties checks to requirements, defines data and roles, prepares recovery, and tests the handover. It controls changes to the process itself so an unreviewed label update cannot quietly invalidate traceability assumptions.
Advanced teams distinguish process controls from measurement controls. They check clock synchronization, denominator completeness, and whether manual fallback records enter the same reports. They also establish review triggers when demand mix or carrier agreements change, because an old stable process can become unsuitable for a new operating context. Automation can make checks timely, but it needs a safe failure mode and an accountable owner. The goal is dependable daily operation with evidence, rather than permanent dependence on project specialists.
07 · Operating conditions and evidence
Operating conditions and evidence
The control plan includes evidence quality. A system-generated timestamp can be precise but wrong if the device clock is unsynchronized or the event is recorded only after a batch upload. Northbank compares a small set of observed loading times with system records and checks how offline events enter the report. This verifies that an apparent improvement is not merely a change in data capture.
The plan also controls who can alter the rules. A lane assignment change, label-format change, or scan bypass permission can weaken the design without changing its visible workflow. Configuration access is limited to authorized roles, changes are recorded, and important modifications trigger renewed verification. Operators have a route to request improvements rather than silently working around awkward instructions. This combination of disciplined change and frontline feedback helps the process remain usable. Sustaining a design does not mean freezing it indefinitely; it means adapting it with evidence and accountable review.
08 · Decision record and next step
Decision record and next step
Northbank evaluates whether checks occur early enough to protect the process. A weekly report of wrong assignments may help learning but cannot prevent the carton already loaded onto a vehicle. The positive confirmation check belongs before loading. The daily summary then supports pattern review and improvement. Different checks have different purposes, and placing all of them in a dashboard does not make their timing interchangeable.
The process owner also checks control burden. If exception review takes so long that supervisors skip it during busy periods, the plan needs redesign rather than stronger reminders. The team observes actual use, simplifies information, and removes redundant checks while preserving requirements. Control preparation includes the resources to perform the checks and the authority to respond. A sustainable control plan fits ordinary operation, provides evidence of performance, and creates a clear route for improving the design when experience shows a better method.
| Control point | Defined evidence | Accountable response |
|---|---|---|
| Before staging | Valid carrier assignment recorded for each carton | Dispatcher holds unresolved release exceptions |
| Before loading | Carton and lane identity agree | Lane lead contains mismatches and follows the reaction plan |
| Daily review | Complete denominators and stratified outcome data | Process owner investigates gaps and controls changes |
Connections
Related methods and phase use
Placed under Improve because of the outcome it supports. Use the method in other phases when its purpose and assumptions fit the work; the phase list is a guide to selection, not a compulsory sequence.
Sources
Professional foundations and further reading
The explanation and fictional teaching examples are written for LeanTrainingLab. Linked primary sources provide professional foundations; example values and local conventions are stated in the guide. The accepted toolset draws on Six Sigma+Lean Toolset, second edition (Lunau, editor; Springer, 2013). No book text or examples are reproduced here.