Definition
Practical Problem Solving (PPS) is a structured PDCA-based method for problems where the problem itself is already clear but the root cause is unknown and requires rigorous investigation. A recurring scrap issue on a specific part, a measurable defect rate that exceeds the target, a known equipment reliability gap — these are PPS problems. The symptoms are visible and the gap is quantifiable. What is not yet understood is why the problem occurs.
PPS is not quick or superficial. A scrap problem with a clear defect pattern may still require days of investigation, multiple rounds of data collection, genba observation, and 5-Why analysis to identify the true root cause. The rigor is the same as TBP — what differs is the starting point, not the depth of thinking.
PPS, TBP, and A3
PPS and TBP follow the same 8-step PDCA logic and share the same steps. PPS was the earlier name for Toyota’s structured problem-solving method; TBP (Toyota Business Practice) was formally adopted around 2005 as the company-wide standard name. In Europe and some Toyota operations, PPS remained the more commonly used term.
In practice, PPS tends to be the term associated with operational and technical problem solving — investigating a clear, defined problem such as a scrap rate, a defect pattern, or an equipment reliability issue. TBP tends to be the term associated with broader business problems that may require clarifying and breaking down before root cause analysis can begin. Whether this represents a formal distinction inside Toyota or simply reflects how different parts of the organization use the same method is not entirely clear.
A3 refers to the communication format — a single A3-sized sheet (11×17 inches) that documents the problem-solving story. Inside Toyota, A3 has historically referred to both the format and the thinking process behind it. Today, A3 is most commonly understood as the format, with TBP or PPS describing the thinking process that the A3 documents.
How It Actually Works
PPS follows the PDCA cycle applied to a clear, specific problem:
Plan — Grasp the current situation through direct observation at the genba. Collect data about the problem — when it occurs, where, on which products, under which conditions. Use stratification (Pareto analysis, check sheets) to focus the investigation on the most significant patterns. Then analyze the root cause using 5-Why analysis, cause-and-effect diagrams, and direct observation. Each “why” must be verified through data or observation, not assumed. Develop countermeasures that address the root cause.
Do — Implement the countermeasure, ideally on a limited scale first to test effectiveness.
Check — Verify that the countermeasure actually resolved the problem. Did the defect rate decrease to the target? Did the scrap issue stop recurring? Compare results against the target defined during Plan.
Act — If the countermeasure worked, standardize it — update the standardized work, train affected personnel, and make the improvement permanent. If the countermeasure did not achieve the target, the root cause analysis was insufficient — return to Plan with the new understanding and investigate further.
The critical discipline is not accepting containment as a solution. Most organizations respond to clear problems with patches — rework the defective parts, adjust the machine, sort the inventory. The problem recurs. PPS demands investigation of why the problem occurs and implementation of countermeasures that prevent recurrence.
Prerequisites
PPS requires supporting systems to function:
Standardized work — Without a standard, there is no way to recognize an abnormality. The standard defines what “normal” looks like. Deviation from the standard is the trigger for PPS.
Visual management — The problem must be visible. Andon boards, process control boards, visual standards, and marked locations all serve to make deviations immediately obvious.
Team leader availability — The team leader must be available to respond within seconds when a problem occurs. This requires adequate staffing ratios and a clear understanding that the team leader’s primary job is responding to and solving problems, not doing administrative work.
A culture that values problem surfacing — Workers must feel safe reporting problems. If reporting a problem results in blame, workers will hide problems rather than surface them, and PPS never gets triggered.
Common Mistakes
Stopping at containment. The most pervasive failure. The problem is patched, the line restarts, and the team leader moves on. No root cause investigation occurs. The problem recurs the next day, the next week, or the next month. The team leader patches it again. This cycle of chronic firefighting is the opposite of PPS.
Solving problems from the office. PPS requires going to the genba and observing the actual condition. A supervisor who responds to an andon activation by asking “what happened?” from their desk and directing a fix by phone is not doing PPS.
Treating PPS as optional. In many organizations, structured problem solving is reserved for “important” problems — the ones that make it onto project lists and receive management attention. Daily problems are handled informally (“just fix it”). At Toyota, daily problems receive structured thinking, not because each one is important in isolation, but because the accumulation of thousands of small improvements is what drives system-level performance.
Not updating the standard after solving the problem. If the countermeasure is not incorporated into the standardized work or process instruction, the improvement exists only in the team leader’s memory. When that team leader is absent — sick, on vacation, transferred — the old method returns and the problem recurs.