问题解决+-Problem+Solving+Tree(ENG).ppt

1、Main Topics,Problem Solving Toolbox 5 Why Is-Is Not Matrix Problem Solving Tree,Problem Solving Tool box - 5 Why,Linkage between 5-Why at a minimum, implement temporary measures.,Part 4: Problem Prevention,Error Proof the root cause. Verify for effectiveness. Capture Lessons Learned.,5 Why-Template,

2、Reference No. _ (Spill, PR/R) Date: _,Team members: Person responsible:,5 Why-Example 1,Directly links the root cause to the Problem Description Machine stops in the middle of its operation (Symptom),Solution: Install pump filter on all machines,Why does machine stop?,Why does fuse keep blowing?,Why

3、 is the circuit overloaded?,Why is there excessive drag?,Why is there insufficient circulating oil?,Why is the pump clogged w/ Metal chips,5 Why-Example 2,小甜饼的味道真差,问题,5 Why-Example 3,杰斐逊纪念馆的大理石由于频繁清洗损坏严重,问题,5 Why-Case Study,ACTIVITY: FLEX INDUSTRIES CASE STUDY Directions: Use the Delphi 5-Why Root C

4、ause Analysis to evaluate the Flex Industries Case Study below and on the following pages. Review the 5-Why analysis template to record your information. Use only the information provided in the case study to complete the 5-Why. Do not try to re-engineer the rivets or solve the technical problems in

5、 the case study. The purpose of this activity is to use the 5-why template to organize the given data and uncover the true root cause(s).,FLEX INDUSTRIES CASE STUDY,Key Players,Jake Quality Manager Janet CSE, Winding River Plant SamTeam Leader, East Line JudyQA Auditor, East Line BenMachine Operator

6、,5 Why-Case Study,Background Jake Ryan is the Quality Manager at Flex Industries. Flex is a component supplier that manufactures metal stampings and light assembly products. The company has a reputation for supplying high quality parts on a consistent basis. Seldom has there been a customer complain

7、t. Flex has Quality representatives called Customer Support Engineers (CSEs) at every customer assembly plant. The CSEs report any problems to Jake for investigation and follow-up. At 7:00 a.m. this morning, Jake received a call from Janet, CSE at the Winding River Assembly Plant. Janet informed him

8、 that the customer had found five defective stabilizing brackets on second shift last night. She checked the remaining inventory and there were no defects in the remaining 326 pieces. The manufacturing sticker on the back of the brackets indicated that they were made by the second shift operator. No

9、rmally, the stabilizing bracket is fastened to the regulator motor with three rivets. The five defective brackets had only two rivets in them. The lower set of rivets on all five brackets was missing a rivet. This could only happen if the automated rivet machine did not place rivet in position . Thi

10、s was the first time that the problem occurred.,5 Why-Case Study,Jake set-up containment procedures at the plant warehouse to sort for discrepant materials. As of this morning, two more defective brackets had been found in the remaining 2019 pieces of inventory at Flex.,Good,Bad,5 Why-Case Study,Cau

11、se Investigation Jake went out to the floor to talk with the team leader of the two rivet lines (East and West) and the area quality assurance auditor. He informed Sam (the team leader) of the quality problem and asked him to identify the line that ran the stabilizing bracket assembly. Sam directed

12、Jake to the East line which ran Winding River assembly brackets only. At the East Line, he spoke with Judy (the QA Auditor for the area) and asked to see the quality log sheets. Jake and Judy reviewed the Nov. 11th log sheet and could not find anything out of the ordinary. He asked Judy to set-up in

13、-house containment procedures to sort for any discrepant material in the finished goods area. Then Jake looked at the control plan to see what the requirements were for checking the bracket. The only required check was to do a dimensional verification at machine set up. Jake decided the next thing t

14、o do was to go to the document control center and look at the PFMEA for the bracket. He needed to find out what failure modes were called out on the PFMEA for missing rivets, thinking this might help him in his investigation. Unfortunately, the only failure mode called out on the PFMEA for missing r

15、ivets was poor set-up, and he already knew the set-up for the bracket had been approved. He even had a sample part from the set-up and the rivets looked fine.,5 Why-Case Study,Next, Jake tried to locate the second shift operator whose clock number was on the defective parts. Since that operator was

16、gone, Jake spoke with the current machine operator (Ben). He asked Ben about any recent difficulties with the rivet machine. Ben said that he hadnt noticed anything out of the ordinary. Ben also mentioned, however, that there had never been any quality bulletins posted in the two years that this par

17、ticular part has been running. Jake decided to stay in the area to watch the machine run for a while. After about 15 minutes, he watched Ben dump rivets into the feeder bowl to prepare for the next run. Shortly after restarting the rivet operation, Ben walked over to another riveter and came back wi

18、th a steel rod. Ben poked around the rivet chute and then continued working. Jake approached Ben and asked him about the steel rod. Ben replied that from time to time the chute gets jammed and he has to clear it out. If the chute got jammed, the automatic machine would fail to load a rivet and place

19、 it in position. This happens two or three times during a shift. He didnt mention this in his earlier conversation with Jake because the problem had existed ever since he started working with this machine. The previous operator showed him how to clear the chute. All the rivet machines were like this

20、 according to Ben. Jake called the Machine Repair Department and asked that someone look at the rivet track. A slight gap in the track was found and removed, and Ben continued to work.,Two hours later, Jake got a call from Ben saying that the track was still jamming. As far as Jake could see, only r

21、ivets were in the bowl. Next, Jake looked into the rivet supplier containers. There was some foreign material in the blue container, but none in the red container. The label on the blue container showed that it was from Ajax Rivet, Inc., and the label on the red container indicated that it was from

22、Franks Fasteners. Obviously, the foreign material was entering the rivet feeder bowl and jamming the track. Jake looked at the operator instructions posted on the job to see if there were any instructions about not using containers with foreign material in them, but there wasnt. Jake called Maintena

23、nce and requested that the bowl be cleaned. He also added the cleaning operation to the preventive maintenance schedule on the equipment. He then called both Ajax Rivet, Inc. and Franks Fasteners. He asked about the cleaning procedures on the returnable containers. Franks did a full container purge

24、and clean. Ajax just re-introduced the containers back into their system. When Jake asked why Ajax did not clean their containers, he was told that Ajax was not aware that such a requirement was needed. It had never been part of the customer requirements document.,5 Why-Case Study,5 Why-Case Study,U

25、pon further investigation, Jake learned that Franks Fasteners supplied other major automotive companies. Since these companies required that all returnable containers be cleaned, Franks instituted the purge as part of its practice for all customers. Ajax Rivet, however, depended primarily on Flex as

26、 its major customer. No such requirement had ever been communicated to them. Jake called the Packaging Department and requested that a container maintenance requirement be drafted which would apply to all their suppliers. He also asked that a machine modification be developed to sense for the presen

27、ce of rivets. Hopefully, this would error proof the process.,5 Why-Case Study,AN EXAMPLE - Part A,A CUSTOMER REPORTED MISSING RIVETS IN A BRACKET ASSEMBLY.,Automated rivet machine did not place rivet in position,Why 1:,Feeder had obstruction,Why 2:,Rivet supplier dunnage had foreign material,Why 3:,

28、Supplier had no maintenance program for dunnage,Why 4:,Supplier not aware of foreign material requirement,Why 5:,WHY DID THE PROBLEM OCCUR?,Path to Investigate Specific Nonconformance,5 Why-Case Study,AN EXAMPLE - Part B,WHY WAS PROBLEM NOT DETECTED?,No inspection required on Control Plan, except se

29、t-up,Why 1:,Not identified on PFMEA as failure mode, except set-up,Why 2:,WE NOW KNOW WHY THE PROBLEM OCCURRED. BUT, IS THERE MORE?,Path to Investigate Lack of Detection,5 Why-Case Study,AN EXAMPLE - Part C,WHY DID THE SYSTEM (QUALITY) ALLOW THIS TO HAPPEN?,Potential failure mode not identified on P

30、FMEA,Why 1:,Incoming dunnage failure modes not addressed,Why 2:,Scope of PFMEA restricted to value add process,Why 3:,WE NOW KNOW WHY THE PROBLEM OCCURRED AND WHY IT WAS NOT DETECTED. BUT, IS THERE MORE?,Path to Investigate system,5 Why-Case Study,B Modify machine to sense for presence of rivets,Les

31、sons Learned: 1. Make supplier part of APQP activities. 2. Make PFMEAs comprehensive of entire system,Reference No. _ (Spill, PR/R) Date: _,from foreign material,Team members: Person responsible:,Problem Solving Tool box - Is-Is Not Matrix,Is-Is Not Matrix,Whats Is-Is Not Matrix? The Is-Is Not matri

32、x is the first “round” of the Dictionary Game. A powerful tool for specifying a problem and laying out the first clues about its root cause. A matrix to summarize what kind of problem did occur, and what might have occurred but did not; where and when it was observed, and where and when it might hav

33、e been observed but was not; etc. A useful tool for the first meeting of a problem solving team, because it puts the collective group knowledge on paper and shows what information is lacking and still needs to be collected.,Why Is-Is Not Matrix? Its the first step toward solving a problem systematic

34、ally, because it lays out what is already known about the problem, in front of the entire problem solving team. Its an efficient way in quick shooting the root cause.,Is-Is Not Matrix,How to use Is-Is Not? Clearly state the problem at hand, in terms of what the current state is versus what the desir

35、ed state is. Gather together a team consisting of people who would know something about the problem. Fill out the Is-Is Not form in a group meeting, at least initially. Fill out the “Is Not” column as well as the “Is” column. List any distinctions in the appropriate column. These distinctions can be

36、 useful clues. List any changes that might have caused the problem to occur. Changes might be in supplier, raw material, machine, procedure, setting, etc. If at any time, multiple problems seem to be appearing, it is OK to create separate Is-Is Not matrices for them. Tree diagram or cause-and-effect

37、 may also be used. Develop action plan to collect any missing information, and to collect data that can back up any hearsay. Assign responsible persons for that. Analyze the completed matrix, try to find out clues. If the problem is not yet solved, develop a problem solving plan based upon the Is-Is

38、 Not matrix. Try to incorporate other tools to find Red-X out.,Is-Is Not Matrix,Is-Is Not Matrix-Example,1a. 问题描述 (站在客户的角度看问题)选择,Is-Is Not Matrix-Case Study,Background Three pieces of Volvo Frond Door harness(P/N: 8697907) were rejected by VCG(Volvo Belgium Plant) respectively on Sep-23-2004, Oct-12

39、-2004 and Oct-15-2004. The reason for rejection is one connector can not be locked with the mating parts. When the final assembly operators at Volvo tried to mate these harness with mating parts, a clear “click” sound could not be heard, and the mating parts could be easily pulled away from each oth

40、ers, which indicated a non-locked connection. The not-locked situation existed after disassembling and reassembling multiple times. The defective harness was originally built at Delphi GZ, then shipped to Delphi Europe, then transported to Volvos plants. Delphi GZ is building both Volvo Front Door h

41、arness and Rear Door harness. The not locked connector mentioned above is used in both front door harness and rear door harness, one each. Sorting has been conducted at Delphi Europe for all harness in stock. Totally 50 pieces defective harness were found.,Directions Fill out an initial Is-Is Not fo

42、rm based upon the above information Any other information needed? Do not try to solve technical problems in the case study.,Problem Solving Tool box - Problem Solving Tree,Problem Solving Tree,Problem Description,Possible Reason,possible,reason,possible,reason,possible,reason,possible,reason,possibl

43、e,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,possible,reason,pos

44、sible,reason,Root Cause,Possible Reason,Possible Reason,A Problem Solving Tree looks like this,Problem Solving Tree,Whats Problem Solving Tree? A tree diagram used to break up a vaguely stated problem into specific source of causes and finally aims at root cause by crossing-off those that do not mat

45、ter. It is similar to Shainins Problem Definition Treesm, Project Definition Treesm, and Solution Treesm. A tree diagram that is mapped down by continuously asking “why” and thinking in the way of “Is-Is Not”. A useful tool for the first meeting and routine meetings of a problem solving team, becaus

46、e it puts the collective group knowledge on paper and shows what information is lacking and still needs to be collected. A systematic way of problem solving by dividing sources of possible causes into logic families, which is powerful and favored by our customers,Problem Solving Tree,How to map a Pr

47、oblem Solving Tree? Start with a summarized problem description, which actually is a project definition. Map the first level of families of possible sources of causes. Break up first level of families into second level of families. Continue above step until the root cause is found. Make splits. (Cro

48、ss-off those families that are not causes of the specific problem, by using any appropriate tools, including Shainin techniques, DPS tools, 6-Sigma, etc.) Finally point at the root cause. Confirm the identity of root cause. Wrap up the investigation.,Note: Rome was not built in one day. Dont try to find out the root cause at the first meeting. All eliminations should be done with professional knowledge or experiments.,Problem Solving Tree-Example,See case study “Burn