Problem Solving Glossary

The international term for a sheet of paper 297 millimeters wide and 420 millimeters long. The closest U.S. paper size is the 11-by-17-inch tabloid sheet.

Cause-and-effect analysis tool used in root-cause analysis to systematically identify potential causes of problems. The technique is especially useful in situations with multiple contributing factors.

Systematic questioning technique that asks "why" repeatedly (typically five times) to drill down from symptoms to root causes.

The process by which leaders coach by asking questions versus providing answers, ensuring responsibility remains with the subordinate to solve the problem by pursuing facts and building consensus. In reality coaches of course back this up with instructions, key points, and advice.

A3 management process is "the key to Toyota's entire system of developing talent and continually deepening its knowledge and capabilities". A management discipline where leaders coach subordinates through problem-solving while developing lean thinking capabilities.

A Toyota-pioneered practice of getting the problem, the analysis, the corrective actions, and the action plan down on a single sheet of large (A3) paper, often with the use of graphics. The power derives not from the report itself, but from the thinking process and organizational learning.

Succinctly states the problem(s) being addressed in one or two sentences. The clear, focused statement that defines what will be addressed in the A3.

A systematic approach to resolving problems or improving work processes that can be followed regardless of whether it's recorded on an A3 document. The term represents the development of culture and mindset required for implementation of the A3 system.

The act and adjust phase of PDCA where successful countermeasures are implemented broadly and lessons learned are captured for future improvement cycles.

Ensuring organizational coherence between individual A3 efforts and broader company goals, strategies, and values. Creating consensus among stakeholders on problems and solutions.

A description of all pertinent information needed to understand the scope of the problem at hand. Provides business context and rationale for why the problem needs attention.

Iterative communication process where ideas and proposals are "thrown" back and forth between levels of the organization to refine understanding and build consensus.

The evaluation phase of PDCA where results are measured against targets and the effectiveness of countermeasures is confirmed through data and observation.

Maintaining logical flow within each A3 report and consistent approaches across different A3s throughout the organization. Prevents contradictory solutions and promotes shared understanding.

Specific actions designed to address root causes and achieve the target condition. Different from solutions in that they are tested and refined through experimentation.

The team develops an understanding of what is currently happening to determine what success will look like. Factual description of the present state without jumping to solutions.

The implementation phase of PDCA where countermeasures and action plans are executed on a small scale or as pilots to test effectiveness.

Ongoing monitoring and adjustment activities to ensure countermeasures remain effective and problems don't recur.

The Japanese term for 'actual place,' often used for the shop floor or any place where value-creating work actually occurs. The real workplace where value is created and problems occur.

Philosophy to see the actual items, rather than have data and presentations about it. Japanese term meaning "actual thing" or "actual object."

Part of Genchi Genbutsu for the actual place. Japanese term meaning "actual place" or "actual location."

Going to the source to check facts for yourself so you can be sure you have the right information you need to make a good decision. Core Toyota principle meaning "go and see for yourself.

Referring to the real or actual situation. Toyota philosophy to go and see the actual facts and conditions. Part of the "Three Gen" terms in Japanese Genchi, Genbutsu, Genjitsu

Detailed action plan specifying who will do what, when, and how countermeasures will be executed, including timelines and resource requirements.

Also referred to as 'autonomation', which means the highlighting of a problem, as it occurs, in order to immediately countermeasure the problem and prevent re-occurrence. It also refers to the concept of separating the human worker from the machine and allow multi process handling.

Continuous improvement philosophy focused on making small, incremental changes that accumulate into significant improvements over time.

Following systematic, rational steps in problem-solving and decision-making. This element ensures that A3 practitioners use structured reasoning rather than jumping to conclusions or relying on intuition alone.

Japanese term for waste - any activity that consumes resources but adds no value from the customer's perspective.

Japanese term for unevenness or irregularity in processes, leading to waste and inefficiency.

Japanese term for overburden or unreasonableness, pushing equipment or people beyond natural limits.

Japanese practice of informal consensus building before formal decision-making, ensuring stakeholder buy-in and smooth implementation.

Statistical technique used to identify the vital few causes that create the majority of problems, following the 80/20 principle.

The systematic management approach that A3 reports are implemented in conjunction with. Toyota views A3 Reports as just one piece in their PDCA management approach, forming the foundation of scientific thinking.

The preparation phase of PDCA where problems are defined, current conditions analyzed, root causes identified, and countermeasures developed before implementation.

A clear, specific description of the gap between current condition and desired state, supported by quantitative data and observable facts.

Focusing on both outcomes and the methods used to achieve them. Understanding that how you achieve results is as important as the results themselves, ensuring sustainable improvement.

The process used to differentiate between facts and opinions regarding a problem's cause and effect. Systematic investigation to identify fundamental causes rather than symptoms.

Simplifying complex information into clear, understandable formats that can be easily communicated and acted upon. The ability to extract key insights and present them visually on a single page.

Understanding broader organizational impact when solving problems. Ensuring that solutions don't optimize one area at the expense of others, but promote the overall good of the organization and its interconnected systems.

Your target and more specifically the goal you are aiming for. You know that your problem-solving effort has been a success if you achieve this level. It is critical to know what metrics will measure success and what the definition of success is.

Reactive troubleshooting situations requiring immediate containment and quick fixes to restore normal operations. The best example is the Andon system in Toyota and the thousands of daily small problems addressed by front line workers and supervisors

Gap closure problems where performance deviates from established standards, requiring structured problem-solving to return to standard. Type 2 problems are often but not always solved using the A3 process.

Target attainment problems focused on achieving higher performance levels through systematic improvement. Type 3 problems are also often but not always solved in conjunction with the A3 thinking process.

Open-ended innovation challenges requiring creative solutions and breakthrough thinking to achieve step-change improvements. Examples can include new products like a Lexus or Prius vehicle or can be smaller but powerful ideas from the workforce.

Five-phase problem-solving methodology used in Six Sigma: Define the problem, Measure current performance, Analyze root causes, Improve the process, and Control to sustain results. Similar to PDCA but with more emphasis on statistical rigor and data-driven decision-making. Typically used for complex process improvement requiring weeks or months.

Eight-discipline team-based problem-solving methodology developed by Ford Motor Company, widely used in automotive and aerospace industries for addressing customer complaints and recurring quality problems. The eight disciplines are: D0-Emergency Response, D1-Team Formation, D2-Problem Description, D3-Containment, D4-Root Cause, D5-Permanent Corrective Actions, D6-Validation, D7-Prevention, D8-Recognition. More reactive and customer-focused than A3, with explicit containment and verification steps.

Structured comparison technique used in problem definition that clarifies boundaries by contrasting what the problem IS versus what it IS NOT across multiple dimensions (What, Where, When, How Much). Example: 'The defect IS on the front panel, IS NOT on rear panels. IS happening on Shift 1, IS NOT on Shift 2.' This contrast reveals clues about root causes and focuses investigation. Core tool in 8D methodology's D2 step.

Immediate temporary actions taken to protect customers from defective products while root cause investigation continues. Examples include 100% inspection, product sorting, shipment holds, or field actions. Different from permanent corrective actions that address root causes. Critical when customer safety or satisfaction is at risk. Part of 8D's D3 discipline and required in most automotive quality systems (IATF 16949).

Specific, measurable characteristics that directly impact customer satisfaction. CTQs translate broad customer requirements (Voice of Customer) into concrete specifications that can be measured and controlled. Example: Customer wants 'fast delivery' translates to CTQ of '95% of orders ship within 24 hours.' Used in Six Sigma DMAIC Define phase to ensure improvement efforts focus on what truly matters to customers.

The extent to which process outputs differ from each other or from target values. Two types exist: Common Cause Variation (inherent to the process, random, requiring system changes) and Special Cause Variation (from specific identifiable sources, addressable through investigation). Understanding variation type is critical for selecting appropriate countermeasures. Attempting to 'fix' common cause variation as if it were special cause leads to tampering and making things worse.

The last point in a process where a defect could have been detected but wasn't, allowing it to reach the customer. Escape point analysis asks 'Why didn't our quality system catch this?' and leads to improvements in inspection methods, work instructions, or control plans. Critical for preventing similar defects in the future. Part of 8D's root cause analysis in D4, but focuses on detection failure rather than creation cause.

Statistical tool that plots process performance over time with calculated upper and lower control limits, used to monitor process stability and distinguish normal variation from signals requiring investigation. Prevents overreaction to normal fluctuations (tampering) while highlighting true problems. Key tool in Six Sigma Control phase and helpful in validating that A3 countermeasures remain effective over time.

Statistical measure that quantifies whether a process can consistently meet customer specifications. Cp measures potential capability (centered process), while Cpk accounts for process centering and is the more practical metric. A Cpk of 1.33 or higher indicates a capable process with margin for variation. Used in Six Sigma to prioritize improvement efforts and validate that countermeasures actually improved the process. Essential for DMAIC Measure and Control phases.

The process of capturing customer requirements, expectations, and feedback to understand what truly matters to them. Methods include surveys, interviews, complaint analysis, and direct observation. VOC translates into Critical to Quality (CTQ) characteristics that guide problem-solving efforts. Starting point for both Six Sigma DMAIC and A3 Background sections. Without clear VOC, teams risk solving the wrong problem or optimizing metrics that don't matter to customers.

High-level process mapping tool that documents Suppliers, Inputs, Process steps, Outputs, and Customers on a single page. Used in Six Sigma DMAIC Define phase and useful for A3 Background sections to establish process scope and boundaries. Helps teams quickly understand what's in scope versus out of scope before diving into detailed analysis. Particularly valuable when process ownership is unclear or multiple departments are involved.

Root cause-based solution implemented in 8D methodology (D5 step) that eliminates the problem permanently, as opposed to Interim Containment Actions that only protect customers temporarily. PCA must address verified root causes from D4 analysis and be validated through testing before full implementation. Similar to A3 Countermeasures but with explicit emphasis on permanence and verification. Not considered complete until proven effective through data collection in D6.

Japanese term meaning horizontal deployment or sideways expansion of successful practices and lessons learned across an organization. In Toyota's system, yokoten is the final step of problem-solving where improvements proven in one area are standardized and spread to similar processes or products. More than simple replication—it involves adapting solutions to different contexts while preserving core principles. Part of A3 Step 8 (Reflection) and essential for organizational learning.

Preliminary step added to modern 8D methodology to assess whether emergency response is needed and if a full 8D is warranted. D0 addresses three key questions: Is immediate action required to protect customers? Is the problem significant enough to justify an 8D? Who should be on the team? Not part of original Ford 8D but widely adopted in automotive industry (IATF 16949). Separates crisis response from structured problem-solving.

First official 8D discipline focused on assembling a cross-functional team with the process knowledge, product expertise, and authority to solve the problem. Team typically includes 3-8 members representing quality, engineering, manufacturing, and affected departments. Requires a Champion (sponsor) to provide resources and remove barriers. Unlike A3 which can be individual work with coaching, 8D explicitly requires team collaboration from the start.

8D discipline that precisely defines the problem using quantitative terms and Is/Is Not Analysis to establish clear boundaries. Answers who, what, when, where, why, how, and how many in measurable terms. Example: 'Front panel paint defects increased from 2% to 8% on Line 3, Shift 1, starting March 15.' Includes photographs, samples, and data. Poor problem description in D2 undermines all subsequent analysis. Similar to A3 Current Condition but more structured.

8D discipline focused on immediately protecting customers from defective products while root cause investigation continues. Actions include 100% inspection, product sorting, shipment holds, enhanced monitoring, or product recalls. Must be implemented quickly (hours to days) and verified effective before moving to D4. Different from permanent corrective actions (D5) which address root causes. Critical when customer safety, satisfaction, or regulatory compliance is at risk.

8D discipline that identifies and proves the root cause through data analysis, testing, or experimentation. Uses tools like 5 Whys, Fishbone Diagrams, data analysis, or designed experiments. Key distinction: Must VERIFY suspected root causes, not just theorize. Verification methods include: recreating the defect by introducing the suspected cause, or confirming defect disappears when cause is eliminated. Also identifies Escape Point (where defect should have been caught). Most analytical and time-intensive 8D step.

8D discipline where the team selects the best Permanent Corrective Action (PCA) to eliminate root causes identified in D4. Must address both the creation cause (why defect occurred) and escape point (why it wasn't detected). Solutions are tested on small scale before full implementation to verify effectiveness without creating new problems. Uses risk assessment (FMEA) to evaluate potential unintended consequences. Similar to A3 Countermeasures but with more explicit verification requirements before rollout.

8D discipline focused on full-scale implementation of verified PCAs and confirming they work in production over time. Includes updating work instructions, training, control plans, and FMEAs. Validation requires data collection over sufficient time period (weeks to months) to prove effectiveness. Interim Containment Actions (D3) can only be removed after D6 validation proves the permanent solution is working. Similar to A3 Implementation & Follow-up but with more rigorous validation requirements.

8D discipline that extends learning beyond the immediate problem to prevent similar issues elsewhere. Asks 'Where else could this happen?' and applies lessons to similar products, processes, or locations before problems occur. Includes updating systems like FMEA, control plans, design standards, and training materials. Reviews whether similar problems happened in the past and weren't adequately addressed. Goes beyond A3 Follow-up by explicitly requiring proactive prevention in other areas (similar to Yokoten).

Final 8D discipline focused on formally closing the project, documenting lessons learned, and recognizing team contributions. Includes celebrating success, sharing results with organization, and archiving documentation for future reference. More formal than A3 closure, often includes management presentation and public recognition. Reinforces problem-solving culture by demonstrating that structured problem-solving is valued. Ensures knowledge is captured before team disbands and members return to regular duties.

Temporary protective action implemented in 8D D3 to protect customers while root cause investigation continues. Synonym for Containment Action but emphasizes the temporary nature—interim until Permanent Corrective Actions (PCA) are validated in D6. Examples include 100% inspection, product sorting, enhanced testing, or shipment holds. Requires resources and can't be sustained indefinitely, creating urgency to complete root cause analysis and implement permanent fixes. Common terminology in automotive quality systems (IATF 16949).

Living document that describes the systematic approach for controlling a process, including what to measure, how to measure it, measurement frequency, who is responsible, and what to do when results are out of specification. Updated as result of 8D D6 and D7 to incorporate lessons learned and prevent recurrence. Different from work instructions (how to do the work) by focusing on verification and reaction plans. Essential element of automotive quality systems (APQP, IATF 16949) and Six Sigma Control phase.

Proactive measures taken to eliminate potential causes of problems before they occur, based on lessons learned from previous issues. Core concept in 8D D7 where teams ask 'Where else could this problem happen?' and take action in similar areas. Different from corrective action (fixing existing problems) by focusing on preventing future problems in other processes, products, or locations. Extends value of problem-solving beyond the immediate issue. Similar concept to Yokoten but with prevention emphasis.

Formal document created in 8D D1 that defines the team's mission, scope, authority, resources, timeline, and success metrics. Includes team member roles, meeting frequency, decision-making process, and escalation path. Prevents scope creep and ensures alignment between team and management expectations. Charter is signed by team Champion (sponsor) and reviewed throughout the 8D process. More formal than typical A3 setup due to 8D's team-based nature and often cross-organizational scope.

First phase of Six Sigma DMAIC where the team defines the problem, project scope, customer requirements (VOC), and business case. Key deliverables include project charter, SIPOC diagram, Critical to Quality (CTQ) characteristics, and preliminary process maps. Answers the question 'What is the problem and why does it matter?' Similar to A3 Background and Theme sections but with more formal documentation. A poorly defined problem in this phase undermines all subsequent analysis and improvement efforts.

Second phase of Six Sigma DMAIC focused on establishing baseline performance and validating measurement systems. Includes Measurement System Analysis (MSA), data collection planning, calculating process capability (Cp/Cpk), and baseline sigma level. Ensures data used for decisions is reliable and repeatable. Answers 'How good or bad is the current performance?' without jumping to solutions. Similar to A3 Current Condition but with explicit focus on measurement validity and statistical baseline establishment.

Third phase of Six Sigma DMAIC where the team uses statistical tools and data analysis to identify root causes of variation and defects. Common tools include hypothesis testing, correlation analysis, regression, and process mapping. Distinguishes vital few causes from trivial many through data-driven analysis. Answers 'What are the root causes of poor performance?' Similar to A3 Root Cause Analysis but with heavier emphasis on statistical verification versus qualitative reasoning. Must prove causation, not just correlation.

Fourth phase of Six Sigma DMAIC where solutions are developed, tested, and implemented to address verified root causes. May use Design of Experiments (DOE) to optimize multiple factors simultaneously. Solutions are piloted on small scale before full deployment to minimize risk. Includes cost-benefit analysis and risk assessment (FMEA). Answers 'What changes will eliminate the root causes?' Similar to A3 Countermeasures and Implementation Plan but with more rigorous experimentation and validation requirements before rollout.

Final phase of Six Sigma DMAIC focused on sustaining improvements through control plans, statistical process control, and standardization. Includes updated procedures, training, mistake-proofing (poka-yoke), and ongoing monitoring with control charts. Prevents backsliding to old performance levels. Answers 'How do we maintain the gains?' Similar to A3 Follow-up Actions and Standardization but with more emphasis on statistical monitoring and documentation. Projects aren't considered complete until controls are in place and validated over time.

Structured experimental methodology that systematically varies multiple input factors to determine their effect on output variables. More efficient than one-factor-at-a-time testing because it reveals interactions between factors. Common designs include full factorial, fractional factorial, and response surface methods. Used in Six Sigma Improve phase and advanced problem-solving when multiple variables interact. Requires statistical expertise but yields powerful insights. Mentioned in your Step 4 RCA article as quantitative multi-variable analysis approach.

Methodology for designing new products, processes, or services to achieve Six Sigma performance from the start, rather than improving existing processes. Uses frameworks like DMADV (Define-Measure-Analyze-Design-Verify) or IDDOV (Identify-Define-Develop-Optimize-Verify). Emphasizes Voice of Customer, robust design, and built-in quality rather than inspection. More proactive than DMAIC which fixes existing problems. Requires different skill set focused on design trade-offs, simulation, and predictive analysis versus reactive problem-solving.

Standard Six Sigma metric that normalizes defect rates across different processes by calculating defects per million opportunities for error. Formula: (Number of Defects / Number of Opportunities) × 1,000,000. A Six Sigma process achieves 3.4 DPMO (99.9997% quality). Allows comparison between simple processes (few opportunities) and complex ones (many opportunities). Example: 10 defects in 1,000 units with 5 defect opportunities per unit = (10 / 5,000) × 1M = 2,000 DPMO (approximately 4 sigma level).

Statistical study conducted in Six Sigma Measure phase to assess whether measurement tools and methods are adequate for their intended use. Evaluates bias, linearity, stability, repeatability (same operator, multiple measurements), and reproducibility (different operators). Common method is Gage R&R study. If measurement variation exceeds 10% of process variation, the measurement system needs improvement before data can be trusted. Critical principle: if you can't measure it reliably, you can't improve it. Must be completed before baseline data collection.

Six Sigma role hierarchy based on training level and project responsibility. Champions are executives who sponsor projects, remove barriers, and allocate resources. Black Belts are full-time quality experts with 4+ weeks statistical training who lead complex projects and mentor Green Belts. Green Belts are part-time practitioners with 1-2 weeks training who lead smaller projects while maintaining regular job duties. Different from A3 coaching model where anyone can lead improvement with management support. Belt certification requires completing projects and demonstrating statistical competency.

Systematic risk assessment tool that identifies potential failure modes in a product or process, evaluates their effects, and prioritizes actions to reduce risk. Assigns Risk Priority Number (RPN) based on Severity × Occurrence × Detection ratings. Two main types: Design FMEA (product design failures) and Process FMEA (manufacturing process failures). Used across all methodologies—8D for evaluating PCAs, Six Sigma Improve phase for risk mitigation, and A3 for assessing countermeasure risks. Essential in automotive (IATF 16949) and aerospace industries.

Classic set of seven fundamental quality tools developed in Japan for data-driven problem-solving and process improvement. The traditional tools are: Check Sheet, Histogram, Pareto Chart, Cause-and-Effect Diagram (Fishbone), Scatter Diagram, Control Chart, and Stratification. These tools form the foundation of quality management and are used across all problem-solving methodologies—A3, Six Sigma, and 8D. Sometimes called the 'Seven Basic Tools of Quality.' Note: Some modern lists substitute Flowchart for Stratification, but the Japanese original uses Stratification.

Simple data collection form designed to systematically record the frequency or occurrence of specific events, defects, or observations. One of the 7 QC Tools. Structures data gathering to reduce errors and make patterns visible. Common types include defect location check sheets, frequency check sheets, and checklist-style forms. Used in DMAIC Measure phase, 8D problem description, and A3 current condition analysis. Converts subjective observations into objective data. Example: tracking defect types by shift, location, or product line.

Bar chart that displays the distribution of numerical data by grouping values into bins or ranges, showing frequency on the vertical axis. One of the 7 QC Tools. Reveals the shape of data distribution (normal, skewed, bimodal), central tendency, and spread. Helps identify whether process output is centered on target and how much variation exists. Used in Six Sigma Measure phase to understand baseline performance and in A3 to visualize current condition. Different from Pareto Chart which ranks categories by impact, histogram shows frequency distribution of continuous data.

Graph that plots pairs of numerical data on X and Y axes to reveal potential relationships between two variables. One of the 7 QC Tools. Shows whether correlation exists (positive, negative, or none) but cannot prove causation. Used in DMAIC Analyze phase, 8D D4 root cause verification, and A3 root cause analysis. Stronger correlation appears as tighter clustering along a line. Example: plotting temperature vs. defect rate to see if relationship exists. Must be followed by statistical analysis or experimentation to confirm causation.

Technique of separating data into meaningful groups or layers (strata) to identify patterns or differences that might be hidden in aggregated data. One of the 7 QC Tools in the original Japanese version. Common stratification factors include time (shift, day, month), location (line, plant, region), operator, supplier, or product type. Reveals whether problems are uniform or concentrated in specific strata. Example: overall defect rate is 5%, but stratifying by shift reveals Shift 2 has 12% while others have 2%. Essential before root cause analysis to focus investigation.

Small voluntary groups of workers who meet regularly to identify, analyze, and solve work-related problems using quality tools and structured problem-solving methods. Originated in Japan in the 1960s and became a cornerstone of Japanese quality management. QC Circles typically use the 7 QC Tools, PDCA cycle, and A3-style problem-solving. Emphasizes worker empowerment, continuous improvement, and bottom-up innovation. Different from management-driven improvement projects by being worker-initiated and focused on immediate work area problems. Builds problem-solving capability throughout the workforce.

The specific location, process step, or moment in time where a defect or problem is actually created or introduced. Also called Point of Occurrence (POO). Different from Point of Detection (POD) where the problem is discovered, and Escape Point where it should have been caught. Understanding POC is essential for effective root cause analysis—fixing detection points prevents escapes but doesn't eliminate the problem at its source. Example: defect created during welding (POC) but discovered during final inspection (POD). Root cause analysis must trace back to POC to implement permanent corrective actions.

The location, process step, or moment in time where a defect or problem is first discovered or identified. Different from Point of Cause (POC) where the problem originates. The gap between POC and POD represents opportunity for improvement—the longer the gap, the more costly the problem becomes. Ideally, POD should be as close as possible to POC through in-process inspection, mistake-proofing, or real-time monitoring. Used in root cause analysis to understand why problems escape detection. Related to Escape Point concept in 8D which asks why existing detection methods failed.

Japanese term meaning 'before-the-fact prevention' or pre-occurrence prevention. Philosophy and practice of anticipating and preventing problems before they occur by analyzing new designs, changes, and potential failure modes. Goes beyond reactive problem-solving to proactive quality built into design and development. Involves analyzing what could go wrong before production starts, using tools like FMEA and DRBFM. Different from inspection-based quality (finding problems after they occur) by preventing problems from being designed in. More comprehensive than just preventing recurrence—aims to prevent first occurrence through systematic anticipation and design robustness.

Systematic change analysis method developed by Toyota that focuses on potential failure modes introduced by design changes, process changes, or new applications. Different from FMEA which analyzes all possible failures in a design. DRBFM specifically targets the delta or change from previous working design, asking 'What changed and what could go wrong because of that change?' Uses GD3 questions: Good Design, Good Discussion, Good Dissection. More efficient than full FMEA when analyzing modifications. Essential tool for Mizen Boshi (pre-occurrence prevention). Requires knowledge of both old and new designs to identify concerns introduced by changes.

Top-down deductive method for analyzing potential causes of system failures using Boolean logic gates (AND, OR). Starts with an undesired top event (the problem) and works backward through contributing factors until root causes are identified. Visualizes all possible paths to failure as a tree diagram. Different from bottom-up approaches like Fishbone which brainstorm possible causes. FTA is more rigorous and quantitative, often used in aerospace, nuclear, and safety-critical industries. Can calculate probability of top event when failure rates of components are known. Complements FMEA by analyzing specific failure scenarios in depth.

Systematic analysis of potential failures in manufacturing or service processes, distinct from Design FMEA which analyzes product design failures. PFMEA examines each process step to identify how it could fail, effects of that failure, and actions to prevent or detect failures. Assigns Risk Priority Number (RPN) based on Severity × Occurrence × Detection. Focus areas include equipment failures, operator errors, material variations, and environmental factors. Used in 8D D5 to evaluate proposed PCAs, Six Sigma Improve phase, and process validation. Essential in automotive (IATF 16949) and required before production launch. Updated throughout product lifecycle as process changes.

Japanese term meaning 'complete your own process' or 'perfection at every step.' Core Toyota principle where each process step must ensure perfect quality before passing work to the next process. The philosophy is that no defects should flow forward—each worker is responsible for verifying their own work meets standards and has authority to stop production if quality issues arise. Different from inspection-based quality where defects are caught later. Emphasizes built-in quality (Jidoka), source inspection, and zero-defect mentality. Prevents defects from multiplying downstream and reduces costly rework. Foundation of Toyota's quality system and key to achieving high quality with minimal inspection.

Problem-solving framework emphasizing thorough problem definition before jumping to solutions. Analyze: systematically break down the problem into component parts and relationships. Quantify: measure performance at appropriate resolution—not too broad to miss patterns, not too narrow to lose context. Detail: specify problem characteristics at the level needed for effective action. Prevents superficial problem statements like 'quality is poor' by forcing specific, measurable descriptions. Used in A3 Current Condition, DMAIC Define phase, and 8D D2 Problem Description. The discipline of AQD ensures teams truly understand the problem before proposing countermeasures, avoiding wasted effort on solutions to poorly understood problems.

Framework for evaluating countermeasure strength from weakest to strongest. Administration (weakest): relies on procedures, training, checklists, and inspections—depends on people following rules consistently. Detection (medium): uses Jidoka, error-proofing (poka-yoke), or in-process checks to catch defects before they escape—catches problems but doesn't eliminate root cause. Prevention (strongest): eliminates the conditions that allow problems to occur, similar to Mizen Boshi philosophy—makes defects impossible rather than detectable. Coaching tool to push teams beyond administrative controls toward true prevention. Example: instead of 'train operators better' (A), aim for 'redesign fixture so part can only be installed correctly' (P).

Japanese term meaning 'mistake-proofing' or 'inadvertent error prevention,' originally coined by Shigeo Shingo. Encompasses both mistake-proofing (preventing wrong actions from occurring) and error-proofing (preventing wrong actions from becoming defects). Poka-yoke devices make it impossible or immediately obvious when something is done incorrectly. Examples include fixtures that only accept parts in correct orientation, sensors that detect missing components, or guides that prevent incorrect assembly. Core principle of Jikotei Kanketsu and key element of ADP framework's Prevention level. More effective than relying on operator vigilance or inspection. Used across all problem-solving methodologies to build quality into processes.

Prevention approach that eliminates the possibility of making an incorrect action in the first place. Focuses on stopping the wrong human action before it occurs. Examples include fixtures designed so parts can only be loaded correctly, connectors with unique shapes that prevent wrong connections, or physical barriers that make incorrect actions impossible. Different from error-proofing which prevents wrong actions from becoming defects. Part of poka-yoke concept. Represents the Prevention level in ADP framework—strongest form of countermeasure because the mistake cannot physically happen. More reliable than training or procedures which depend on human consistency.

Detection approach that prevents incorrect actions from becoming defects that reach the customer or next process. Assumes mistakes may occur but catches them immediately before consequences propagate. Examples include sensors that detect missing parts, vision systems that verify correct assembly, or alarms triggered by out-of-specification conditions. Different from mistake-proofing which prevents wrong actions from occurring. Part of poka-yoke concept. Represents the Detection level in ADP framework—stronger than administrative controls but weaker than true prevention. Used when mistake-proofing is not technically or economically feasible. Enables Jikotei Kanketsu by catching errors in-process.

Problem-solving framework that operationalizes Genchi Genbutsu into three action steps. Go and See: physically visit the Gemba (actual place) where work happens and problems occur—don't rely on reports or second-hand information. Get the Facts: observe actual conditions (Genjitsu) and actual objects (Genbutsu)—measure, photograph, collect data firsthand. Grasp the Situation: synthesize observations into deep understanding of current reality before proposing solutions. Also called 'Three Actuals' or 'San Genjitsu Shugi' in Japanese. Prevents jumping to conclusions based on assumptions or conference room analysis. Essential for A3 Current Condition, DMAIC Measure phase, and 8D Problem Description. Coaches use 3G's to redirect teams away from speculation toward direct observation.