Quality Improvement - Problem Solving Process and Lean Tools

Problem

The root cause or underlying issue that, if resolved, would eliminate the symptom

Sympton

The observable effect or consequence of the problem

Errors in problem solving

Type I, Type II, Type III

Type I Error

Solving a problem that does not exist

Type II Error

Failing to recognize a problem exists

Type III Error

Solving the wrong problem, addressing a symptom or a misidentified issue, but the root cause remains unsolved

Solving a problem

The opportunity to improve the process, better to have a structured approach for more complicated problems

Types of Quality Problems

1. Conformance problems

2. Efficiency Problems

3. Product Design Problems

4. Process Design Problems

5. Unstructured Performance Problems

Conformance Quality Problems

Failure to meet specs or customer expectations; ensuring outputs align with requirements (doing things right)

Efficiency Problems with Quality

Suboptimal use of resources (time, labor, materials) to achieve conformances (about doing things efficiently)

Product Design Problems

Designing new products or redesigning existing products to better satisfy customer needs

Process Design Problems

Designing new processes or substantially redesigning existing processes

Unstructured performance problems

Unsatisfactory performance by processes that are not well specified or understood

Common Approaches to problem solving

DMAIC process → Conformance problems

Lean production → Efficiency Problems

DMAIC Process

Used in the Six Sigma approach, specifically for conformance problems, since the processes that create the problems can be easily identified, measured, analyzed, and changed (most known process improvement method)

DMAIC Steps

1. Define: What is Wrong?

2. Measure: How bad is it?

3. Analyze: Why is it happening?

4. Improve: fix it

5. Control: Keep it fixed

DMAIC - Step 1: Define

• Identify the problem: What is wrong, who/what is affected, and what evidence proves it?

• Define the process: What process needs improvement, what are the objectives, and what does success look like?

• Problem statement: State the current performance, undesirable condition, size of the gap, and timeframe. No causes, blame, or solutions.

• Goal statement: Set a specific, measurable target with a timeframe, focused only on the desired outcome.

• Process map: Show the current process being improved.

• SIPOC diagram: Identify the Suppliers, Inputs, Process, Outputs, and Customers to establish the scope of the process.

• Value-stream map: Map the process in detail to show how work/material/information flows through it and identify the process to be improved.

• Main purpose: Use data and evidence to prove the problem exists and is significant enough to address.

SPIOC Diagram (Useful tool for DMAIC Step 1)

Used to identify the scope of the process

Process Map

An organized visualization of all interrelated activities which combine to form a process

Value Stream Mapping (VSM)

A special type of process map, a tool used to identify areas of improvement in a process by identifying added-value activities and eliminating waste

Value-added activity

Transforms or shapes material or information or people
Done right the first time!
The customer wants it (Seek to emphasize)

Non-Value-Added Activity (Necessary)

No value is created, but it cannot be eliminated based on current technology, policy, or thinking (necessary waste) (Seek to minimize)

Non-Value-Added Activity (Pure Waste)

Consumes resources, but creates no value in the eyes of the customer (wait time, inventory, rework) (Seek to eliminate)

Different Types of Waste

1. Over production

2. Inventory

3. Transportation

4. Unnecessary Movement

5. Waiting

6. Defective outputs

7. Over Processing

8. Unused employee creativity

Over production

Creating more material, info, tests, or treatment than needed

Inventory

More material or info than needed

Transportation

Moving material, info, or people

Unnecessary Movement

Moving employees to access or process material, info, or people

Waiting

Waiting for material, info, or work in process waiting to be processed

Defective outputs

Errors or mistakes causing the effort to be redone to correct the problem

Over processing

Taking unnecessary steps in a process

Unused employee creativity

Losing improvement opportunities by not engaging or listening to employees

DMAIC - Step 2: Measure

• Measure current performance: How bad is the problem now?

• Choose reliable metrics: Decide what to measure and how to measure it accurately.

• Collect needed data: Gather trustworthy data for later analysis.

• Validate the measurement system: Make sure the data and measuring methods are accurate.

• Establish a baseline: Create a clear picture of current process performance.

• Common tools: Check sheets, run charts, and Pareto charts.

DMAIC - Step 3: Analyze

• Find root causes: Determine why the problem is happening.

• Identify variation drivers: Find the factors affecting performance.

• Validate important causes: Determine which causes actually matter.

• Common tools: Flowcharts, scatter diagrams, cause-and-effect diagrams, root-cause analysis, and Pareto charts.

Flow Charts

Used to define and understand how a process works, used to identify inefficiencies in a process like bottlenecks, redundant steps, etc. (chronological sequence of steps, decisions, and actions involved in a process)

Scatter Diagram

A plot for identifying a potential relationship between two variables (x and y)
Data are collected in pairs, then plot y against x
Shape indicates the type of relationship that may exist between the two variables

Cause and Effect Diagram

(AKA Ishikawa Diagram AKA fishbone diagram)

• Shows a chain of causes and effects.

• Used during brainstorming to identify possible causes of a problem.

• Problem/effect goes at the end of the main line.

• Main branches show possible causes.

• Smaller branches show contributors to those causes

DMAIC - Step 4: Improve

• Generate solutions: Brainstorm ways to remove or reduce the root cause.

• Encourage creativity: Consider all ideas, even unusual ones.

• Evaluate options: Compare proposed solutions.

• Select the best solution: Choose the most promising idea to implement.

DMAIC - Step 4.5 - Goals

• What changes will eliminate or reduce the root cause?

• Which solution is most effective?

• What are the risks?

• Does the solution actually improve performance?

(Checklists, design of experiments)

DMAIC - Step 5: Control

• Solutions are implemented

• focus is on how to maintain the improvements, which might include establishing new standards and procedures and additional training to workforce

(Control charts are an example)