EG7322 Lean EngineeringSession 2: The Lean Mental ModelMarina MarinelliMEng MSc PhD FHEAm.marinelli@leicester.ac.ukLean production, means doing more with less —less time, less space, lesshuman effort, less machinery, less materials— while giving customers what theywant.Initially Lean started in the Automotive Industry ‐ basedon Toyota Production System ‐ TPSNow Lean is implemented in any type ofManufacturing …and services as wellWHAT IS LEAN?Simply, lean means creating more value for customers withfewer resourcesIt is about efficiency and effectivenessIt is delighting customersLEAN IS A MINDSETIt is not a ‘quick fix’It is a philosophy – a way of life1. Define VALUE from the customer’s perspectiveand provide what they want2. Identify the VALUE STREAM or process for each product or service andreduce or eliminate steps that do not add value3. Align the value‐added steps so they FLOW continuously4. Allow the level of customer demand to PULL the process, i.e. produce onlywhat is ordered5. Pursue PERFECTION through continuous improvementLean PrinciplesCurrentstateIdentifywasteEliminatewasteFuturestateFull of waste Only value added activitiesLean Culture / thinking / mental model• Kaizen• Problem solving• Plan‐do‐check‐act (PDCA)• Organisational culturea command or principle intended especially as a general rule of action.• Kai = to change• Zen = to make better• Quality begins with the customer. But the customers’ views are continuallychanging and standards are rising, so continuous improvement is required.• Even if something isn’t broken, it can and must be improved.• Everyone has a role, from top management to shop floor employees. Kaizen tapsinto the tacit knowledge of all staff, surfacing this knowledge to make it explicit.Kaizen spirit” comprises three things:1. Cheerfulness: No matter how tough things are today, tomorrow will be better.We’ll keep improving, and we’ll solve our most difficult problems.2. Go see: We experience things firsthand. We get out of the office and into the Gemba.We work with frontline team members with respect and humility.3. Get your hands dirty: We learn by doing. We roll up our sleeves and try stuff. We runexperiments to prove cause and effect. Then we lock in countermeasures. Lastly, weshare what we’ve learned.The act of continuous, incrementalchange and improvementLean Culture / thinking / mental modelThe philosophy of kaizenPDCA is the core activity of management.
A manager’s job is to practice and teach PDCA.The best managers practice PDCA on a daily basis.PDCA thinking must inform all our activities from day‐to‐day kaizen, to problemsolving, to strategic planning.Deming introduced PDCA to theJapanese in his 1954 lectures to theJapanese Union of Scientists andEngineers. Deming credited hismentor Walter Shewhart, uponwhose initial research‐design‐produce‐sell cycle PDCA was based.Walter Shewhart, 1939, StatisticalMethod from the Viewpoint ofQuality Control.Plan —Select a process for improvement, analyse it and plan a change that will havebeneficial effect.Do — Apply the change on a small scale, a test case. No mandatory changes before theeffects are clear.Check — Observe the effects of the change. The project team must fully understand theeffects of the change, why they occurred, and how they might affect some other process inthe system.This analysis is so important that Deming changed the title to“study” later in life.Act — If the results are as expected (if they show theintended beneficial effect), implement the changesystem‐wide STANDARD.If the results are not as expected, move forward in thecycle to the plan step and revisit the process to analyze itagain and prepare a new plan. This new plan will be basedon better information, knowledge about what did notwork.PDCAWalter Shewhart, 1939, Statistical Methodfrom the Viewpoint of Quality Control.Who, What, Where,When, Why and How Clarify the Problem Initial Problem Perception(Large, vague, complicated problem)The “Real” Problem Locate Area /Point of Cause PoCDirect CauseWhy ? CauseWhy ?CauseWhy ? CauseCause Countermeasure Root CauseWhy ?Why ?CauseInvestigationGrasp theSituation5 Why ?Investigation ofRoot CauseBasic Cause & EffectInvestigationGrasp theSituationCauseInvestigationLean problem solving process PDCA PlanDetermine goals for a process and needed changes to achieve them.To plan we must determineWhere do we want to go?How do we get there?Grasping the Situation (GTS) Have we defined the purpose of our plan or activity clearly?Have we linked our purpose to our organization’s overall purpose?Do we have a clear picture of our current condition?Do we have a clear picture of our target condition? Is our plan doable with our current resources?What good and bad things could happen along the way,and how will we react?What is the current capability of our people?What training is required to raise their capability?Related questions includeWhat are the checkpoints and milestones along the way?PDCAHow do we achieve these?GEMBAPDCAUsed to express the practice of thoroughly understanding a condition byconfirming information or data through personal observation at thesource of the condition.“Walking the flow,” allows the team members to identify where problemsexist in the present state of affairs. Go to the place of action (GEMBA WALK) OBSERVE directly Ask QUESTIONS“Actual place,” ‐ any place where value‐creating work actually occurs. Go to the place of action (GEMBA WALK) OBSERVE directly Ask QUESTIONS How do you do this work? How do you know that you are doing it correctly? How do you know that the outcome is defect free? What do you do if you have a problem? Who do you communicate with? How do you know what to do next? What signals cue your work? Do you do this in the same way as others?“Six honest serving men taught me all I knew, theirnames are WHAT & WHY & WHEN & WHERE & HOW &WHO”GEMBA Grasp the situation5 Ws and 1 H:Determine goals for a processand needed changes to achievethem.PDCAWho, What, Where,When, Why and How Clarify the Problem Initial Problem Perception(Large, vague, complicated problem)The “Real” Problem Locate Area /Point of Cause PoCDirect CauseWhy ? CauseWhy ?CauseWhy ? CauseCause Countermeasure Root CauseWhy ?Why ?CauseInvestigationGrasp theSituation5 Why ?Investigation ofRoot CauseBasic Cause & EffectInvestigationGrasp theSituationCauseInvestigationLean problem solving process PDCAWho, What, Where,When, Why and How Clarify the Problem Initial Problem Perception(Large, vague, complicated problem)The “Real” Problem Locate Area /Point of Cause PoCDirect CauseWhy ? CauseWhy ?CauseWhy ? CauseCause Countermeasure Root CauseWhy ?Why ?CauseInvestigationGrasp theSituation5 Why ?Investigation ofRoot CauseBasic Cause & EffectInvestigationGrasp theSituationCauseInvestigationLean problem solving process PDCAWithout repeatedly asking why, managers would simply replacethe fuse or pump and the failure would recur.The specific number five is not the point. Rather it is to keepasking until the root cause is reached and eliminated.Cause and effect relationshipsFive Whys: The practice of asking “why?” repeatedly whenever a problem isencountered in order to get beyond the obvious symptoms to discover the rootcause.Machine stoppedworking WHY?There was an overloadand the fuse blew WHY?The bearing was notsufficiently lubricated.WHY?The lubrication pumpwas not pumpingsufficientlyThe pump was worn WHY?WHY? and rattlingThere was no strainerattached and metalscraps got in.We made 900 units versus WHY?a target of 1,200Delays/defectsMaterial Machines Methods MotherSubcauseSubcausenatureMeasurements Manpower Fishbone diagram: Tool tobrainstorm and document rootcauses of an effect or problem groups the causes intotypical categories(Procedures)(People)(Policies)(InformationSystems)(Places)Cause and effect relationshipsCauseSubcauseCauseSubcauseCauseCauseSubcauseCauseCauseSubcauseCauseSubcauseCauseSubcausePDCAPDCACause and effect analysis is generally used in the following situations:• To identify key characteristics and key process parameters affecting the output• To help the group to reach a common understanding of a problem• To expose gaps in existing knowledge of a problem• To reduce the incidence of subjective decision‐making• To help employees to know more about the process and the problemsbeing studiedCause and effect relationshipsWhen many factors/causes are impacting a problem, a Pareto analysis canbe used for the following:• Find out the most important item/defect• Determine ratio of each item to the whole• Identify where to take actionsThe basic principle of Pareto is ‘80 percent of overall effect is contributed by 20percent of causes’. Hence, Pareto analysis helps to sort out the ‘vital few’ fromthe ‘trivial many’.For performing a Pareto analysis, the following steps can be used:• Define a problem and collect data on the factors that contribute to it.• Historical records generally provide sufficient information.• Arrange the data in descending order and calculate the cumulativepercentage.• Draw the horizontal and vertical axes.• Prepare a bar graph in the X‐axis with descending order of frequency.• Draw a cumulative percentage graph.Cause and effect relationshipsThe basic principle of Pareto is ‘80 percent of overall effect is contributed by 20percent of causes’. Hence, Pareto analysis helps to sort out the ‘vital few’ fromthe ‘trivial many’.Customer Survey ‐ RestaurantLengthy food delivery timeLong queue at the tillAbsence of salt and napkinsDelay in cleaning tablesWaiter unhelpful and rudeFood price too highNo free refill optionMenu only in englishFood not tasty4 563487 6 2 4 3Vital fewTrivial manyTrivial manyTotal comments: 142The Pareto principlestates that, for manyevents, roughly 80% ofthe effects come from20% of the causes.Pareto diagram / principle63487 5 4Lengthy fooddelivery timeLongqueueat thetill AbsenceNo freeDelay inof salt andcleaningrefillnapkinsoptiontables Waiterunhelpfuland rude6050403020100 4 3 2FoodpricetoohighMenu onlyin englishTotal comments: 1426Foodnottasty0%20%40%60%80%Pareto diagram / principleA Pareto diagram is a bar graph, and each bar represents a category. The bars are rank ordered in descending order fromleft to right. A line going upward from the first category shows the cumulative percentage distribution i.e.the proportion ofthe total number of complaints accounted for as each successive category is added.The Pareto principle states that, for many events, roughly 80%of the effects come from 20% of the causes.100%63487 5 4Lengthy fooddelivery timeLongqueueat thetillAbsenceof salt andnapkinsDelay incleaningtablesWaiterunhelpfuland rude6050403020100 4 3 2FoodpricetoohighNo freerefilloptionMenu onlyin english T comments: 1426Foodnottasty0%100%20%40%60%80%63/142=44%+ 48/142=78%+ 7/142=83%Pareto diagram / principleA Pareto diagram is a bar graph, and each bar represents a category. The bars are rank ordered in descending order fromleft to right. A line going upward from the first category shows the cumulative percentage distribution i.e.the proportion ofthe total number of complaints accounted for as each successive category is added.The Pareto principle states that, for many events, roughly 80%of the effects come from 20% of the causes.Who, What, Where,When, Why and How Clarify the Problem Initial Problem Perception(Large, vague, complicated problem)The “Real” Problem Locate Area /Point of Cause PoCDirect CauseWhy ? CauseWhy ?CauseWhy ? CauseCause Countermeasure Root CauseWhy ?Why ?CauseInvestigationGrasp theSituation5 Why ?Investigation ofRoot CauseBasic Cause & EffectInvestigationGrasp theSituationCauseInvestigationLean problem solving process PDCAA change in the current system that addresses thespecific root cause(s) and is designed the preventrecurrence of the problemHypothesisIf we do ………….., the resultwill be …………….NEMAWASHI• The process of gaining acceptance and preapproval for a proposal by evaluatingfirst the idea and then the plan, with management and stakeholders• to get input, anticipate resistance, and align the proposed change with otherperspectives and priorities in the organization.Nemawashi literally translates as “going around the roots”Its original meaning was literal: digging around the roots of a tree, to prepare it for atransplant. This process involves bringing the dirt from the new location, andintroducing it to the tree, before the transplant, so the tree can grow accustomed tothe new environment before it gets there.PDCADoImplement the changes.Do contains its own PDCA cycle. This reflects the importance of pilot activities.A good pilot allows us to strengthen and confirm our plan before full implementation.This approach contrasts with the “just do it” mindset.CheckEvaluate the results in terms of performance.We must decideWhom to check withWhat to checkWhen to checkHow frequently to check In what manner to checkPDCA“Go see” is also fundamental. We must not rely on paper reportsor hearsay.We must go see what is actually happening.We must eliminate the possibility of failure through checking.If we do …………..,the result will be …………….We will measure this by ……….ActReflect (hansei) on the condition after checking and take appropriate action:Adopt: Standardize when both outcome and process results are on target.Adjust: Make countermeasures when either outcome or process results are substandard. Abandon: try something else if the test proves that the countermeasure doesn’t workReflection entails honest humble acceptance of successes and failures, strengths andweaknesses, and a sincere commitment to do better.Organizational Culture“All for one and one for all” is a stirring mantra.• Uniforms. All team members wear the same uniform irrespective of position.• No executive offices and no walls. Toyota offices are typically one large roomcontaining rows of desks. Managers, technical specialists, and executives typically sitelbow to elbow.• No executive dining rooms or parking spaces.• Genchi genbutsu. The “go see” spirit ensures that managers and senior managers arein constant contact with shop floor team members.• Employment security. There is an implicit guarantee to the effect that only in the mostsevere circumstances and as a last resort would job cutbacks be considered.Lean Culture / thinking / mental model• Change is hard; change hurts.• Most people are decent and hardworking and want do what’s right.• Most of the problem is in the system, not the people.Lead with a “light touch,” informed by the following beliefs:The light touch expresses fundamental decency and respect for people,absent which, you can’t sustain much.5 key principlesof the Toyota employee conduct guidelinesLean Culture / thinking / mental modelhttps://global.toyota/en/company/vision-and-philosophy/toyotaway_code-of-conduct/Thank you
