6.6 Problem Solving and Decision Making

6.6 Problem Solving and Decision Making

1. Problem-Solving Process

Problem Identification Phase

  1. Problem Recognition:

    • Detecting deviations from expected performance.

    • Identifying symptoms vs root causes.

    • Gathering initial data and observations.

  2. Problem Definition:

    • Clearly stating the problem in specific terms.

    • Establishing problem boundaries and constraints.

    • Determining what constitutes a "solution."

  3. Goal Setting:

    • Defining success criteria.

    • Establishing measurable objectives.

    • Setting realistic timelines.

Analysis and Solution Development

  1. Root Cause Analysis:

    • 5 Whys Technique: Asking "why" repeatedly to drill down.

    • Fishbone Diagram (Ishikawa): Categorizing potential causes (Man, Machine, Method, Material, Measurement, Environment).

    • Fault Tree Analysis: Logical diagram of failure pathways.

  2. Information Gathering:

    • Collecting relevant data.

    • Researching similar problems.

    • Consulting experts and stakeholders.

  3. Solution Generation:

    • Developing multiple potential solutions.

    • Considering various approaches.

    • Evaluating feasibility of each option.

Implementation and Evaluation

  1. Solution Selection:

    • Applying decision-making tools.

    • Considering risk, cost, and benefits.

    • Choosing the optimal solution.

  2. Implementation Planning:

    • Developing action steps.

    • Assigning responsibilities.

    • Creating timelines and milestones.

  3. Execution:

    • Implementing the chosen solution.

    • Monitoring progress.

    • Making adjustments as needed.

  4. Evaluation and Learning:

    • Measuring outcomes against goals.

    • Documenting results and lessons learned.

    • Standardizing successful solutions.

2. Brainstorming

Preparation Phase

  1. Define Clear Objective:

    • Specific problem statement.

    • Desired outcomes.

    • Constraints and limitations.

  2. Assemble Team:

    • Diverse perspectives (5-10 people optimal).

    • Mix of expertise levels.

    • Include both experts and fresh thinkers.

  3. Set Ground Rules:

    • No criticism during idea generation.

    • Encourage wild ideas.

    • Build on others' ideas.

    • Aim for quantity over quality initially.

Idea Generation Techniques

  1. Traditional Brainstorming:

    • Free-flowing verbal idea sharing.

    • Round-robin or open format.

    • Time-limited sessions (15-45 minutes).

  2. Brainwriting (6-3-5 Method):

    • 6 people write 3 ideas each in 5 minutes.

    • Pass papers and build on others' ideas.

    • Silent, reduces dominance by vocal participants.

  3. Structured Approaches:

    • SCAMPER Technique:

      • Substitute

      • Combine

      • Adapt

      • Modify

      • Put to another use

      • Eliminate

      • Reverse

    • Morphological Analysis: Breaking problem into parameters and exploring combinations.

Post-Brainstorming Activities

  1. Idea Capture:

    • Record all ideas without filtering.

    • Use whiteboards, sticky notes, or digital tools.

    • Assign unique identifiers to each idea.

  2. Initial Filtering:

    • Group similar ideas (affinity diagramming).

    • Eliminate clearly impractical suggestions.

    • Identify promising concepts.

  3. Refinement:

    • Develop promising ideas further.

    • Combine complementary concepts.

    • Add details and specifications.

3. Decision Matrix and Decision Tree

Decision Matrix (Pugh Matrix)

  1. Structure:

    • Rows: Alternative solutions.

    • Columns: Evaluation criteria.

    • Cells: Scores/ratings for each alternative against each criterion.

  2. Construction Steps: a. List Alternatives: All potential solutions. b. Identify Criteria: Relevant factors for decision-making. c. Weight Criteria: Assign importance weights (sum to 1 or 100%). d. Establish Baseline: Select reference alternative (often current state). e. Score Alternatives: Rate each alternative against criteria. f. Calculate Weighted Scores: Score × Weight for each cell. g. Sum and Compare: Total weighted scores for each alternative.

  3. Scoring Methods:

    • Relative Scoring: + (better), 0 (same), - (worse) relative to baseline.

    • Numerical Scales: 1-5, 1-10, or 0-100 scales.

    • Pairwise Comparison: Comparing alternatives two at a time.

  4. Example Criteria Categories:

    • Technical: Performance, reliability, safety.

    • Economic: Cost, ROI, payback period.

    • Implementation: Time, complexity, resources.

    • Risk: Probability of failure, consequences.

Decision Tree Analysis

  1. Basic Structure:

    • Decision Nodes: Squares (choices under decision-maker's control).

    • Chance Nodes: Circles (probabilistic outcomes).

    • End Nodes: Triangles or endpoints (final outcomes with values).

    • Branches: Lines connecting nodes.

  2. Construction Process: a. Identify Decision Points: Key choices to be made. b. Identify Uncertain Events: Probabilistic outcomes. c. Determine Probabilities: Estimate likelihoods for chance events. d. Assign Values: Numerical outcomes (costs, benefits). e. Calculate Expected Values: Working backward from endpoints.

  3. Expected Monetary Value (EMV) Calculation:

    • For chance nodes: EMV=(Probability×Value)EMV = \sum (Probability \times Value)

    • For decision nodes: Choose branch with highest EMV.

    • Example: EMV=(0.7×$100,000)+(0.3×$20,000)=$64,000EMV = (0.7 \times \$100,000) + (0.3 \times -\$20,000) = \$64,000

  4. Types of Decision Trees:

    • Single-Stage: One decision point.

    • Multi-Stage: Sequence of decisions over time.

    • With and Without Probabilities: Deterministic vs stochastic.

  5. Sensitivity Analysis:

    • Testing how changes in probabilities or values affect decision.

    • Identifying critical assumptions.

    • Determining decision robustness.

Comparison and Application

  1. When to Use Each Tool:

    • Decision Matrix: Best for multi-criteria decisions with multiple alternatives.

    • Decision Tree: Best for sequential decisions with uncertainty.

  2. Limitations:

    • Matrix: May oversimplify complex trade-offs.

    • Tree: Becomes unwieldy with many branches.

    • Both: Depend on quality of input data and assumptions.

  3. Combined Approach:

    • Use matrix to evaluate alternatives.

    • Use tree to analyze implementation paths.

    • Iterate between tools for complex decisions.

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