5.3 Management & Planning Tools

5.3 Management & Planning Tools

In 1976, the Japanese Union of Scientists and Engineers (JUSE) formalized the 7 New Quality Control Tools (also known as the 7 Management & Planning Tools). While the classic 7 QC tools focus primarily on quantitative numerical data, the 7 Management & Planning tools structure qualitative, verbal, and conceptual data to facilitate strategic planning, complex project management, and cross-functional problem solving.

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1. Affinity Diagram (The KJ Method)

Developed by anthropologist Jiro Kawakita, the Affinity Diagram organizes a large volume of unstructured ideas, opinions, or survey responses into natural, conceptual groupings based on implicit relationships.

• Execution Process:
  1. State the objective or problem statement clearly.
  2. Brainstorm ideas silently on individual sticky notes.
  3. Group notes silently into natural clusters based on perceived affinity.
  4. Assign a descriptive header card to each cluster.
• CQE Application: Ideal for synthesizing messy Voice of Customer (VOC) data or organizing root causes during early project scoping.

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2. Interrelationship Digraph (ID)

The Interrelationship Digraph maps complex, multidirectional cause-and-effect relationships among interconnected factors. Unlike linear fishbone diagrams, the ID allows for feedback loops and multi-factor dependencies.

• Analysis Method:
  • Draw arrows from cause to effect ($A \rightarrow B$).
  • Count incoming arrows (In-degrees) and outgoing arrows (Out-degrees) for each node.
  • Key Driver (Root Cause): Node with high outgoing arrows and low incoming arrows.
  • Key Indicator (Outcome): Node with high incoming arrows and low outgoing arrows.

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3. Tree Diagram (Systematic Diagram)

A Tree Diagram systematically breaks down a broad goal, customer requirement, or problem statement into increasing levels of detail (from strategic to tactical to operational).

                             +---> Task 1.1
               +---> Sub-Goal 1
               |             +---> Task 1.2
  Main Goal ---+
               |             +---> Task 2.1
               +---> Sub-Goal 2
                             +---> Task 2.2

• CQE Application: Essential in Quality Function Deployment (QFD) for expanding primary customer requirements into secondary and tertiary technical requirements, or in Fault Tree Analysis (FTA) for failure breakdown.

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4. Matrix Diagram

A Matrix Diagram depicts the multi-dimensional relationships and interaction strengths between two or more sets of factors. It forms the core structure of the House of Quality in QFD.

Matrix Formats

• L-Type Matrix: 2 sets of items evaluated in a 2D grid (Rows vs. Columns).
• T-Type Matrix: 3 sets of items where 1 primary set is evaluated against 2 secondary sets.
• X-Type Matrix: 4 sets of items evaluated in a closed cross grid.
• Y-Type Matrix: 3 sets of items evaluated in a 3D cube layout.

Standard relationship weighting values: Strong ($,\odot, = 9$), Medium ($,\bigcirc, = 3$), Weak ($,\triangle, = 1$).

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5. Prioritization Matrix

A Prioritization Matrix combines the structural grid of a matrix diagram with quantitative criteria weighting (such as Analytical Hierarchy Process or Decision Matrix Scoring) to evaluate and rank alternative solutions against weighted criteria.

Math Application: Weighted Decision Scoring

Given $m$ options evaluated across $n$ criteria with criteria weights $w_j$ ($\sum w_j = 1.0$) and option scores $s_{ij}$:

$\text{Total Score}_i = \sum_{j=1}^{n} w_j \times s_{ij}$

Scenario Table:

Option A is selected based on highest total weighted score (7.55 vs 6.90).

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6. Process Decision Program Chart (PDPC)

A Process Decision Program Chart (PDPC) systematically identifies potential failures, obstacles, and risks along a proposed process flow before implementation, specifying contingency countermeasures for each risk.

• Structure: Process Steps $\rightarrow$ Potential Risks/Failures $\rightarrow$ Countermeasures $\rightarrow$ Feasibility Assessment ($O$ for feasible, $X$ for infeasible).
• CQE Application: Serves as a qualitative precursor to formal Failure Mode and Effects Analysis (FMEA).

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7. Arrow Diagram (Activity Network Diagram)

An Arrow Diagram (or Activity Network Diagram) models project schedules using Critical Path Method (CPM) or Program Evaluation and Review Technique (PERT) nodes to sequence tasks, calculate float times, and identify the critical path.

PERT Time Estimation Formula

Given Optimistic time ($a$), Most Likely time ($m$), and Pessimistic time ($b$):

$\text{Expected Time } (t_e) = \frac{a + 4m + b}{6}$ $\text{Variance } (\sigma^2) = \left( \frac{b - a}{6} \right)^2$

Critical Path & Float Equations

$\text{Total Float (Slack)} = \text{LS} - \text{ES} = \text{LF} - \text{EF}$

Where:

• $\text{ES}$ = Early Start, $\text{EF}$ = Early Finish ($\text{EF} = \text{ES} + t_e$)
• $\text{LS}$ = Late Start, $\text{LF}$ = Late Finish ($\text{LS} = \text{LF} - t_e$)
• Critical Path: The continuous path of activities with zero total float ($Slack = 0$). It dictates the minimum project duration.

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Comparison: Classic 7 QC Tools vs. 7 Management & Planning Tools