Problem Solving

RI ASQ May 15, 2008 Dinner Meeting

Angelo G. Scangas

Quality Support Group, Inc.

www.qualitysupportgroup.com

978-430-7611 [email protected]

1

Step 2: Describe the Problem

“A problem well defined is a problem half solved” • A complex problem can not be solved or addressed until it is completely understood and documented.

Step 2: Describe the Problem

• The problem description covers a broad range of criteria: – Who is experiencing the problem? – What is the problem?

– When did the problem occur?

– Where did it occur?

– Why did the problem occur? (preliminary) – How big is the problem? How much? How many?

• These components are consolidated into the abbreviation 5W’s and 2H’s.

Step 2: 5W2H

• Who? – Identify the customers (internal or external) that are experiencing the problem or registering the complaint.

– Which groups are impacted by the effect of the problem?

• What? – Classify the problem in terms of an object and the defect. Determine the part or object in question?

Step 2: 5W2H

• Where? – Where was the defect found? Which plant? Which line? Which state? Which customer location?

– If there is a defective part: Where is the defect located? • Note: A concentration (“measles”) chart may be very helpful.

Step 2: “Measles Chart”

connector label Unseated Screws found at PDI Screws inserted at Screw Cell 1 Screws inserted at Screw Cell 2

Note: The root cause (s) must fully account for our complete problem description.

Step 2: 5W2H

• When? – Analyze control charts, run charts and/or shipment records to determine exactly when the problem began.

– Ask whether the problem occurs on all shipments or only specific shifts or days of production?

– Is the issue seasonal? Has this problem previously occurred during the same time of year?

– Or has the problem been present since the start of production?

Step 2: 5W2H

• Why? – This is meant to capture known explanations or preliminary “gut” feelings.

– These preliminary hypotheses should be captured for later analysis. • Note: All potential root causes will be examined against the problem description to determine whether it accounts for the problem and jibes with the data.

Step 2: 5W2H

• How much? How many? – Determine the magnitude of the problem.

– How much nonconforming material was sent to the customer? How many parts were defective?

– What was the defect count?

– What is the percent defective?

• Compare the magnitude of the problem to prior baseline defect rates.

– Did something change in our process or has the problem been present from the start of production?

Step 2: 5W2H

5W2H Who?

What?

Where?

OBJECT & DEFECT GEOGRAPHICAL & ON PART

When?

Why? (optional) How much or how many?

# OF DEFECTS OUT OF TOTAL (%)

Step 2: Preliminary List of Causes • Begin assessment of the potential causes for the defect

– Fishbone diagrams will be the predominant tool in this analysis.

Step 2: “Is/Is Not” • The most common tool in comparative analysis is called “Is/Is Not.” • “Is/Is Not” is based on asking paired questions:

– “What is happening?” – “What could be happening but is NOT.

Step 2: “Is/Is Not”

• Example: – (Q1) “Who is experiencing the problem?” • (A1) “Our customers in the Southwest.” – (Q2) “Who could be experiencing the problem – but is not?” • (A2) “Our customers in Ireland” – Analysis/Thought process: What accounts for the difference between the Southwest and Ireland? Perhaps climate differences? Are the process flows the same? Is error-proofing used in one stream and not the other?

– Get Information and clear-up any missing facts.

Description of problem

WHO (What customer) WHAT

(Object) -- name the object that is having the trouble. (Defect) -- name the trouble or problem that the object is having.

WHERE

(Seen on Object). Where on the object is the problem occurring (inside, outside, top, bottom, etc. Where in the process flow did the problem 1st develop. Describe all other places w/regards to where the object and the trouble can be found.

(Seen geographically) Name the place where the object with the trouble can be found. Name the place where it 1st showed up. Name all other places where this problem occurs/occurred.

WHEN

(First Seen) When with respect to time did the trouble/problem 1st occur -- day, month, year, time of day etc. Describe any patterns in time. Describe when in the process the trouble 1st occurred. When in the lifecycle. (When else seen) Describe other places in process and life cycle where the trouble or problem was observed. Consider all units of time such as hrs, days, min, s, shift, period, quarter, year.

When seen in process (life cycle)

HOW BIG/HOW MANY

(How many objects have the defect? ) Describe the size of the problem/effect. Describe the number of objects that have or have had the trouble. How many defects per object? Describe the magnitude of the trouble in terms of percentage, rates, yield, dimensions, etc. Describe the physical dimensions of the defect or problem.

What is the trend? What is the pattern?

Problem Statement (What's wrong with what) IS IS NOT GET INFORMATION ON COMMENTS/THEORY

Step 2: Problem Statement

• The problem statement or deviation statement is an expression of the difference between what is expected (customer specification) and what actually happened.

Step 2: Comprehensive Problem Description

• The problem statement is a dynamic entity. It is modified as the problem is further understood.

– The team will revise and update it as the problem solving progresses. • Problem Statements must be as specific as possible – avoid generalities.

– Do not include your proposed root cause or potential solution. This will be derived later.

– Avoid reference to root cause.

Step 4: Identify Root Cause (s)

• Objective – To identify and test potential causes of the problem using the detailed problem description and data to isolate and validate the true root cause (s).

• There are many tools that need to be employed in this process.

– Problem Solving practitioners should be familiar with the following concepts and methods: • Process flows/VSM, Control Plans, FMEA, Standard Operating Procedures, Fishbone/C&E Diagrams, Pareto Analysis & Histograms, Control Charts, Capability and Gage Studies, Scatter Plots, brainstorming etc.

• Design of Experiments and advanced statistical tools may be required depending on the complexity of the problem. In this case: A LSS black belt should be included on the team.

Step 4: Basic Steps

The Basic Steps in Determination of the Root Cause: • Generation – Review the problem definition (5W2H) and Is/Is-Not looking for potential occurrence causes.

– Ask “What Changed”?

– Review the process flow for clues to potential root causes. – Brainstorm potential causes using a “fishbone” diagram.

• Refinement – Prioritize the list of potential causes and compare them to the problem description for consistency.

– Employ the 5Whys.

• Verification – Test the prioritized list of causes. Consider conducting investigations in parallel to reduce time.

– Verify the root cause (s) through experimentation.

– Review the cause (s) to insure a full accounting of the problem description.

Step 4: Generation

Continuously ask “What Changed”? • Unless the problem has existed all along (common cause) – something must have changed.

Example: In the case of the LS console – what changed?

The plastic? The press? The temperature?

Step 4: Generation

• • • • • • • • Continuously ask “What Changed”? What changed in the process flow?

What changed in the equipment?

What changed in the supply base?

What changed in the mode of transportation?

What changed in personnel?

What changed in calibration?

What changed in terms of process capability?

What changed in the weather? Was it unusual?

Focus on the distinctions in the Is/Is-Not analysis!

Step 4: Generation -- PF Review

Review the process flow for potential clues and potential causes.

•Review each step along the flow and ask what could cause the effect or problem.

Step 4: Cause and Effects Diagram

Brainstorm potential causes using a “fishbone” diagram.

The head of the fish is labeled with the problem or the effect. The major bones of the fish are categories of potential causes.

There are two primary labeling practices: • Mark the major bones with broad categories such as the classic 6M’s – methods, machines, materials, manpower, measurements and mother-nature. Then brainstorm potential causes and mark them on the small bones.

Step 4: Cause and Effects Diagram

Materials Manpower Measurements Inadequate gaging and calibration for machine settings Pins vs CMM and new fixturing Pour-on foam (age, wear, thickness, unevenness) Adhesive thickness, chemistry, physical characteristics Aluminum Ys, profile and thickness Plastic cover profile Contacting adhesive in the tab region Cover placement Alignment of press Handling and shipping of adhesive tab Mother Nature Adhesive exposure and storage Methods Location of plastic cover in top nest Inadequate PM procedure including replacement of foam, etc Inadequate press set-up procedures/checksheets Vacuum Profile of nests Dwell time Uneven pressure -- insufficient pressure @ edges Location or Alignment of the pins Movement of the grippers creating a bias Speed of retraction of the back plunger Machines delamination  Key variables from CE diagram from the delamination problem:  Dwell time, adhesive exposure, Poron foam thickness (pressure)

Step 4: Refinement (“Funneling”) The fishbone may contain many potential causes. This list will need to be narrowed down to a manageable list of causes to be tested.

How?

•Compare the list of potential causes to the problem definition for consistency.

– Eliminate those causes that are inconsistent.

Refinement

• • • Employ the 5 Whys The 5 Whys is a tool that assists in moving from the problem statement and effects of the problem to the true root cause.

It is used in conjunction with the fishbone diagram analysis in moving from the chosen root cause to the true root cause. Simply ask Why 5 times starting with the effect of the problem.

Example: Why did the console delaminate? The glue was stripped from the plastic cover.

If you stopped: The cause would seem to be the glue!

Step 4: “5 Whys”

As you can see: 5 Whys focuses the investigation toward true root cause and away from mere effects of the problem. Example II: A functional tester lost power. Why?

The power cord got pulled out.

Corrective Action: Re-insert cord and retrain all operators.

Would this be a robust and permanent corrective action?

Step 4: “5 Whys”

Would this be a robust and permanent corrective action?

No. Simply replacing the cord is attacking a symptom.

Why did the cord come loose?

It was kicked loose.

Why? The cord is long and runs on the floor Why? The nearest available power supply is across the aisle.

Step 4: “5 Whys”

Is there even a more robust answer?

Corrective Action: Install a power source under the tester to eliminate contact.

5Whys drives us to a permanent corrective action. At the center is the most robust solution.

Step 7: Prevent Problem Recurrence

• It is critical to look systematically at the problem and the root cause and to modify our methods and practices at the highest level.

– For example: An error-proofing device was turned off on line A for product #1 -- thereby allowing defective material to ship to the customer.

– It is critical to look for systemic issues: • Why was error proofing turned off?

• What part of the broad management system -- including policies, procedures, training methods, core processes, etc. - may be implicated?

• What actions would you undertake?

Step 7: Prevent Problem Recurrence

• Addressing the systemic root cause involves: – Asking the question: “What management system failed and allowed the problem to occur and to escape?” – Correcting the management system that failed.

• Systemic root cause deals with “drilling deep” into why the system failed. – Why did the development and planning process not predict the defect?

– Why did the manufacturing process not prevent the defect?

– Why did the quality process not protect the customer from the defect?

– Note: Use the 5 Whys approach to each of these questions to determine systemic causes.

Step 7: Prevent Problem Recurrence Feasibility/Design Timing/Implementation Process/Logistics Was Problem ID'd @ PPAP?

Did we quote appropriately?

Did we use a cross functional team?

Was cost estimated correctly?

Did we ID previous fails during APQP?

Did we ID fails @ supplier?

How is employee changeover rate?

Did we understand customer reqs?

Is mgt. change Was customer approval received for change?

frequent?

Is this an input to another process?

Have we ID'd all interfaces?

Did we consider risk to all areas of product and process functionality?

Did we fail to utilize recommendations?

Is PM being deprioritized?

Were all areas of product and process ID'd on PFMEA?

Did we test the appropriate # of samples?

Did we have appropriate resources for launch?

Is cycle time realistic?

Did we track design changes?

Did we fail to consider risks?

Are tool changes communicated? Was operator understanding of process verified?

Did quote include all costs in meeting customer reqs?

Were tests performed under realistic conditions?

Systemic Root Cause Repair, rework, start-up, engineering changes Was contingency plan in place & effective?

Was handling or traceability properly considered?

Was product knowledge fully transferred to mfg?

Did we fail to act on out-of-control signals?

Was scrap fully analyzed?

Did we provide complete training?

Was handling properly considered?

Did we fully considered potential supplier failures?

Were Have we made any system or design changes?

Were failures from APQP sample runs properly analyzed?

expectations communicated?

Did we remove containment w/out proper validation?

Did we fail to isolate suspect product?

Was labelling properly considered?

company What kind of attitude is represented to mfg?

Were risks properly considered?

Was the issue ID'd during APQP?

Have we ID'd all internal and inter interfaces?

Off Standard Operations/Lean Packing & Shipping Verification/Plant Tryout Customer Return System/Comm'n/Contacts

Step 7: Prevent Problem Recurrence

• Steps need to be taken to monitor the product and the process to insure that the problem does not return.

 Process/System audits should be established to verify all of the controls and SOP’s determined in the 8D.

 Product and System should be audited on an ongoing basis to insure long-term control of the problem.

Thank You!

Angelo G. Scangas

Quality Support Group, Inc.

www.qualitysupportgroup.com

978-430-7611 [email protected]