5-WHY PROBLEM SOLVING PROCESS
PRACTICAL PROBLEM SOLVING
Introduction ē In the Delphi organization, a common problem solving process is used to analyze and solve quality problems. Delphi 舱麓ず场, 盽ノ拜肈秆∕筁祘砆ノㄓだ猂㎝秆∕珇借拜肈 There are four major parts of the process: 筁祘Τ璶场だ: ? Grasp the Situation ? 秆薄猵 ? Cause Investigation ? 秸琩 ? Problem Correction ? 拜肈タ ? Prevention through Error-proofing ? ň岿箇ň ? Grasp the Situation ? 秆薄猵 During the first part of the process, you: 筁祘材˙, 璶: ? Identify the Problem ? 絋粄拜肈 ? Clarify the Problem ? 络睲拜肈 ? Locate the Point of Cause (PoC) ? 琩т拜肈 (PoC) ? Cause Investigation ? 秸琩 In the second part of the process, you: ? Conduct a “5-Why” investigation to identify the root cause ? for the specific problem ? for why the problem was not detected ? for why the system” allowed the problem to occur ? 龟琁 “5ぐ” よ猭秸琩ㄓ絋粄セ ? ぐ拜肈穦祇ネ ? ぐ拜肈翴⊿Τ砆浪代ㄓ ? ぐ╰参す砛拜肈祇ネ
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5-WHY PROBLEM SOLVING PROCESS ? Problem Correction ? 拜肈タ In the third part of the process, you: ? Take specific action to correct the problem. At a minimum, short-term temporary measures are required to protect the customer. 筁祘材˙, 璶: ? 疭﹚惫琁ㄓタ拜肈 ぶ惠璹祏戳羬┦惫琁ňゎ拜肈 祇ネ惠璶玂臔臮. ? Prevention Thru Error-proofing ? ň岿箇ň In the fourth part of the process, you: ? Take specific action to make sure the problem cannot recur, typically through errorproofing ? Capture Lessons Learned 筁祘材˙璶: ? 疭﹚惫琁絋粄拜肈ぃ穦祇ネ, ㄥň岿よ猭 ? 痙┮厩毙癡
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5-WHY PROBLEM SOLVING PROCESS
PRACTICAL PROBLEM SOLVING MODEL 龟悔拜肈秆∕家Α 5 Why Funnel 5ぐ筁耾
PROBLEM IDENTIFIED (Large, Vague, Complicated) Problem Clarified
G R A S P T H E C A U S E
S I T U A T I O N I N V E S T I G A T I O N
?
Area of Cause Located Point of Cause ( PoC ) Why? 1 Cause Why? 2 Cause Why? 3 Cause Why? 4 Cause Why? 5
Where in the process is problem occurring? “Go See” the problem Basic Cause/Effect Investigation
5 Why?
Investigation of Root Cause
Why did we have the problem?
Why did it get to the customer?
Why did our “system” fail?
?
Root Cause
?
Corrective Action
?
Lessons Learned
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5-WHY PROBLEM SOLVING PROCESS
BASIC STEPS OF PRACTICAL PROBLEM SOLVING 龟悔拜肈秆∕膀セ˙艼 Part I – Grasp the Situation 材场だ – 秆薄猵 ? Step 1: Identify the Problem In the first step of the process, you become aware of a problem that may be large, vague, or complicated. You have some information, but do not have detailed facts. Ask: ? ˙艼 1: 絋粄拜肈 Identify the problem 筁祘材˙, 秨﹍種醚拜肈約獂┦家絢┦確馒┦Τㄇ獺 ぃ笵ㄆ龟灿竊璶拜: ? What do I know? ? ヘ玡秆ぐ? ? ? Step 2: Clarify the Problem ? ˙艼 2: 络睲拜肈Clarify the Problem The next step in the process is to clarify the problem. To gain a more clear understanding, ask: 筁祘˙琌络睲拜肈眔睲捶粄醚璶拜 ? What is actually happening? ? What should be happening? ? 痷龟祇ネぐ? ? 盢祇ネぐ? ? ? Step 3: Break Down the Problem ? ˙艼 3: だ秆拜肈 Break down the problem At this point, break the problem down into smaller, individual elements, if necessary. 硂翴碞琌弧Τゲ璶盢拜肈だ秆Θ灿じ. ? What else do I know about the problem? ? Are there other sub-problems? ? и临璶秆ぐ? ? Τ⊿Τㄤ妮拜肈? ? ? Step 4: Locate the Point of Cause (PoC) ? ˙艼 4: 琩т拜肈(PoC) Now, the focus is on locating the actual point of cause of the problem. You need to track back to see the point of cause first-hand. Ask: 瞷礘翴琩т硂拜肈玻ネ璶翴惠璶發萝ㄓ秆璶翴 も戈ㄓ 拜: ? Where do I need to go?
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5-WHY PROBLEM SOLVING PROCESS ? ? ? ? ? What do I need to see? Who might have information about the problem? и惠璶ń? и惠璶ぐ? 街秆硂拜肈?
? Step 5: Grasp the Tendency of the Problem ? ˙艼 5: 磝搐拜肈 To grasp the tendency of the problem, ask: 磝搐拜肈镣墩 璶拜: ? Who? ? Which? ? When? ? How often? ? How much? ? 街? ? ? ? ぐ? ? Ω? ぶ计秖? It is important to ask these questions before asking “ Why?” 拜ぐ ぇ玡拜硂ㄇ拜肈璶 Part II: Cause Investigation 材场だ: 秸琩 ? Step 6: Identify and confirm the direct cause of the abnormal occurrence. ? ˙艼せ: 懦絋粄钵盽祇ネ钡. If the cause is visible, verify it. If the cause is not visible, consider potential causes and check the most likely causes. Confirm the direct cause based on fact. Ask: 狦陪 玥龟. 狦ぃ陪玥璶σ納㎝浪琩程 ㄆ龟膀娄絋粄钡璶拜 ? Why is the problem occurring? ? Can I see the direct cause of the problem? ? If not, what do I suspect as potential causes? ? How can I check the most likely potential causes? ? How can I confirm the direct cause? ? ぐ拜肈穦祇ネ? ? иǎ 钡? ? 狦ぃ琌ぐ琌и胔好? ? и浪琩程? ? и絋粄钡?
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5-WHY PROBLEM SOLVING PROCESS ? Step 7: Use 5-Why investigation to build a chain of cause/effect relationships that lead to the root cause. Ask: ? ˙艼 7: ノ5ぐ秸琩よ猭ㄓ篶硑/挡狦闽羛渺ㄓтセ 璶 拜: ? Will addressing the direct cause prevent recurrence? ? If not, can I see the next level of cause? ? If not, what do I suspect as the next level of cause? ? How can I check and confirm the next level of cause? Will addressing this level of cause prevent recurrence? ? 匡拒钡箇ň祇ネ盾? ? 狦ぃ琌и秆糷盾? ? 狦ぃ琌и胔好糷琌ぐ? ? и浪琩㎝絋粄糷? ? 皐癸糷ㄓ箇ň祇ネ盾 If not, continue asking 揥hy?” until you find the root cause. 狦ぃ琌膥尿拜ぐ祇瞷セ Stop at the cause that must be addressed to prevent recurrence. Ask: 既氨皐癸ゲ斗箇ň祇ネ璶拜: ? Have I found the root cause of the problem? ? Can I prevent recurrence by addressing this cause? ? Is this cause linked to the problem by a chain of cause/effect relationships that are based on fact? ? Does the chain pass the therefore” test? ? If I ask hy?” again, will I be into another problem? ? и竒т拜肈セ盾 ? и皐癸ㄓ箇ň祇ネ盾? ? 硄筁ㄆ龟膀娄狦渺渺钡拜肈盾? ? 渺狦闽╰盾 ? и拜ぐи盢穦拜肈盾? ? Have I found the root cause of the problem? ? Can I prevent recurrence by addressing this cause? ? Is this cause linked to the problem by a chain of cause/effect relationships that are based on fact? ? Does the chain pass the therefore” test? ? If I ask hy?” again, will I be into another problem? Be sure you have used 5-Why Investigation to answer these questions: 睲贰竒ノ5ぐ秸琩よ猭ㄓ氮硂ㄇ拜肈 ? Why did we have the problem? ? Why did the problem get to the customer? ? Why did our system” allow it to occur? ? ぐиΤ拜肈? ? ぐ拜肈穦め? ? ぐи╰参す砛ウ祇ネ?
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5-WHY PROBLEM SOLVING PROCESS
5 WHY CAUSE INVESTIGATION 5ぐ秸琩
Abnormal Occurrence Why? 材Ω
钵盽祇ネ
(cause/effect relationship) (狦闽╰)
C
C
C
C
Why? 材Ω
Direct Cause
钡
(cause/effect relationship) (狦闽╰)
C
C
C
C
Why? 材Ω
Cause (cause/effect relationship) (狦闽╰) Cause Why? 材Ω (cause/effect relationship) (狦闽╰) Cause Why? 材きΩ
C
C
C
C
C
C
C
C
C
Root Cause
セ
Therefore Test 狦代刚
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5-WHY PROBLEM SOLVING PROCESS
Step 8: Take Specific Action to Address the Problem ˙艼 8: 皐癸拜肈疭﹚惫琁 Use temporary measures to eliminate the abnormal occurrence until the root cause can be addressed. Ask: ノ羬惫琁玠埃钵盽祇ネセ砆矗拜 ? Does it contain the problem until a permanent solution can be implemented? ? ウ筀拜肈祇ネ戳癸郸砆磅︽盾? Implement corrective actions to address the root cause to prevent recurrence. Ask: 皐癸セ磅︽タ惫琁ㄓ箇ň祇ネ拜 ? Does it prevent the problem? ? ウ箇ň拜肈祇ネ盾? Follow-up and check results. Ask: 尿︽笆㎝浪琩挡狦拜: ? Is the solution working? ? How do I know? ? 秆∕よ磅︽盾? ? и秆? ?
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5-WHY PROBLEM SOLVING PROCESS
PRACTICAL PROBLEM SOLVING CHECKLIST 龟悔拜肈秆∕琩浪 To be sure you have followed the problem solving model, use this checklist as you complete the problem solving process. 絋獺ノ拜肈秆∕家ΑЧΘ拜肈秆∕筁祘叫ノ硂琩浪 Grasp the situation 秆薄猵 ___ Pick-up the problem. 莉眔拜肈. ___ Clarify the problem. 络睲拜肈 ___ Break down the problem. だ秆拜肈. ___ Locate the Point of Cause (PoC). 琩т拜肈(PoC). ___ Grasp the tendency of the problem. 磝搐拜肈镣墩.
Cause Investigation 秸琩 ___ Identify/confirm the direct cause. 懦/絋粄钡. ___ Ask 5 Why's to identify the root cause. 拜 5 ぐ或ㄓ絋粄セ ___ Ask 5 Why's for Why the problem was not detected and reached the customer?” 拜 5 ぐ或皐癸 ぐ或拜肈⊿Τ砆浪代ㄓτめ? ___ Ask 5 Why's for Why did the system allow the problem to occur?” 拜 5 ぐ或皐癸ぐ或 ╰参穦す砛拜肈祇ネ? Problem Correction 拜肈タ ___ Implement corrective action; at a minimum, implement temporary measures 磅︽タ惫琁ぶ璶磅︽羬惫琁
Prevention 箇ň ___ Error-proof the root cause. セň岿 ___ Capture Lessons Learned. 癘魁┮厩毙癡
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5-WHY PROBLEM SOLVING PROCESS
ACTIVITY: FLEX INDUSTRIES CASE STUDY
Directions: ? Use the Delphi Problem Solving Process to evaluate the Flex Industries Case Study below and on the following pages. Review the 5-Why Investigation results on Page 11. Use the worksheets on Pages 13 and 14 to record your work. Use only the information provided. Do not try to re-engineer the rivets or solve the technical problems in the case study. The purpose of this activity is to use the Problem Solving model to organize the given data.
? ? ?
FLEX INDUSTRIES 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 complaint. Flex has Quality representatives called Customer Support Engineers (CSE抯) at every customer assembly plant. The CSE抯 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 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. Normally, 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 was the first time that the problem occurred.
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5-WHY PROBLEM SOLVING PROCESS
GOOD
BAD
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.
Cause 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 which runs the stabilizing bracket assembly. Sam directed Jake to the East line which runs Winding River assembly brackets only. At the East Line, he spoke with Judy (the QA Auditor for the area) and asked to see th the quality log sheets. Jake and Judy reviewed the Nov. 11 log sheet and could not find anything out of the ordinary. He asked her to set-up in-house containment procedures to sort for any discrepant material in the finished goods area. Next, Jake tried to locate the second shift operator whose clock number was on the defective parts. Since that operator was gone, Jake spoke with the current machine operator (Ben). He asked Ben about any recent difficulties with the rivet machine. Ben said that he hadn抰 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 particular 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.
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5-WHY PROBLEM SOLVING PROCESS
Shortly after restarting rivet operations, Ben walked over to another riveter and came back with 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. This happens two or three times during a shift. He didn抰 mention this in his earlier conversation with Jake because the problem has existed ever since he started working with this machine. The previous operator showed him how to clear the chute. All the rivet machines are like this. 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 rivets 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 Frank抯 Fasteners. Obviously, the foreign material was entering the rivet feeder bowl and jamming the track. Jake called Maintenance 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 Frank抯 Fasteners. He asked about the cleaning procedures on the returnable containers. Frank抯 did a full container purge 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 policy was needed. Upon further investigation, Jake learned that Frank抯 Fasteners supplies other major automotive companies. Since these companies require that all returnable containers be cleaned, Frank抯 instituted the purge as part of its practice for all customers. Ajax Rivet, however, depends primarily on Flex as its major customer. No such policy has ever been required of them. Jake called the Material Control Department and requested that a container maintenance policy be drafted which would apply to all their suppliers. He also asked that a machine modification be developed to sense for the presence of rivets. Hopefully, this would errorroof the process. KEY PLAYERS
Jake Janet Sam Judy Ben Quality Manager CSE, Winding River Plant Team Leader, East Line QA Auditor, East Line Machine Operator
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5-WHY PROBLEM SOLVING PROCESS 笆: 褐ㄓ吹穨╯ 弧: ? ノ眔拜肈秆∕筁祘ㄓ蝶︳褐ㄓ吹穨糵115ぐ 秸琩挡狦 ノ13㎝14癘魁 度ノ矗ㄑ. 硂╯ńぃ璶刚瓜穝砞璸筭皏┪秆∕мズ拜肈 笆ヘノ 拜肈秆∕家Αㄓㄏ倒戈Τ兵瞶 褐ㄓ吹╯
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5-WHY PROBLEM SOLVING PROCESS
狽璹瞅棒よ猭ㄓ縵匡紅砯Τ畉钵さΝゎ眖2019褐ㄓ吹. 砯い祇瞷2ぃ▆や琜
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5-WHY PROBLEM SOLVING PROCESS
硄筁瞏秸琩, 狽秆 猭孽ㄑ砯倒ㄤ耕═óそ眖硂ㄇそ璶― ┮ΤΜ甧竟璶砆睲间 猭孽絋﹚睲瑍Μ甧竟Θ篋ㄒ(皐癸┮Τめ)荷恨ㄈヒ 吹ゑ耕ㄌ苦褐ㄓ吹ウㄤ璶め妓眖ゼ砆璶―Τ硂妓も琿
狽筿杠硄北场璶―璹甧竟蝴 も琿ㄓ矗ㄑ倒┮Τㄑ莱坝 璶―诀竟秈︽э秈ㄓ稰莱筭皏琌 篅硂盢琌ňゎ筁祘岿
狽 Janet ﹊ 甫 痁
璶 Θ
珇借竒瞶 めや祘畍, 鸟紅 恨, 狥絬 珇玂絔,狥絬 诀竟 穨
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5-WHY PROBLEM SOLVING PROCESS 5-Why Cause Investigation
Reference No. _______________ (Spill, PR/R…) Date: ____________________
Lessons Learned: 1. Make supplier part of APQP activities. 2. Make PFMEA抯 comprehensive of entire system 59959549.doc 12/1/99
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5-WHY PROBLEM SOLVING PROCESS
Delphi 5-Why Template to be used for all 5-Why Investigations
5-Why Analysis5- ぐ 秸琩
Reference No. __________ (Spill, PR/R…) Date: ____________________
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5-WHY PROBLEM SOLVING PROCESS
FLEX INDUSTRIES WORKSHEET
GRASP THE SITUATION秆薄猵 Activity (Step) ︽笆 (˙艼) What did they know? 笵ぐ? Identify the problem 絋粄拜肈 Clarify the problem 络睲拜肈 Break down the problem だ秆拜肈 Locate point of cause (geographic location) 琩т拜肈翴 (瞶竚) Grasp tendency of the problem (What questions are you asking?) 秆拜肈镣墩 What did they do? 暗ぐ?
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5-WHY PROBLEM SOLVING PROCESS
CAUSE INVESTIGATION Activity (Step) ︽笆 (˙艼) Identify/confirm the direct cause 懦/絋粄钡 Ask 5 Why to identify the specific root cause associated with the problem 拜 5 ぐㄓ絋粄籔拜肈闽 絋セ Ask 5 Why for why the problem was not detected and reached the Customer 拜 5 ぐㄓ絋粄ぐ拜肈⊿ Τ砆浪代ㄓ笷めêń Ask 5 Why for why the 攕ystem” allowed it to happen 拜 5 ぐㄓ絋粄 ぐ ╰参穦 す砛拜肈祇ネ Implement temporary measures to protect the Customer 磅︽羬惫琁: 磅︽惫琁ňゎ拜肈Ωめ êń Implement corrective actions
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秸琩
What did they know? 笵ぐ?
What did they do? 暗ぐ?
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