Lean, CMMI and Choosing a Methodology

Lean and Six Sigma. ASQ's comparison is short: "Lean focuses on waste reduction, whereas Six Sigma emphasizes variation reduction" (Chapter Eighty-Nine, on statistical SQA and Six Sigma). The two are often combined as lean Six Sigma.

CMMI

CMMI is a model of the practices of organisations that develop products well; this book has used its process areas throughout Module 2, from process and product quality assurance (Chapter Eighty-Six, on SQA activities) to causal analysis and resolution (Chapter Eighty, on using defect data). Its owners describe it as "Originally created for the U.S. Department of Defense to assess the quality and capability of their software contractors". The version quoted here, CMMI for Development v1.3 (SEI, 2010), has 22 process areas; later versions exist, and the CMMI Institute, now part of ISACA, says the model "is continuously updated", so the levels and process areas below are v1.3's.

Two representations. In the staged representation an organisation is rated on maturity levels, each defined by a set of process areas; in the continuous representation each process area is rated separately on capability levels. In v1.3's words: "Maturity levels are used to characterize organizational improvement relative to a set of process areas, and capability levels characterize organizational improvement relative to an individual process area."

The five maturity levels.

Level 1 organisations, CMMI notes, often produce products that work, but "frequently exceed the budget and schedule documented in their plans", and success "depends on the competence and heroics of the people in the organization and not on the use of proven processes." CMMI's advice on moving up is firm: "each maturity level forms a necessary foundation for the next level, trying to skip maturity levels is usually counterproductive."

IDEAL. CMMI suggests that planning an improvement programme can begin "with an improvement approach such as the" IDEAL model, whose name stands for Initiating, Diagnosing, Establishing, Acting and Learning. The five phases are a PDCA cycle at the scale of a whole organisation: start the programme, find where the organisation stands, plan the changes, make them, and learn from the result.

Worked example: ExamReg's software house on the staged scale

The earlier chapters of this book contain evidence of which CMMI v1.3 process areas ExamReg's software house practises: an SQA group that audits processes, a causal analysis loop, reviews, testing at every level, measurement. They also contain its gaps: no agreement with its payment gateway's provider, no organisation-wide standard processes or training records (Chapter Ninety-Five, on ISO 9001). The program records this book's reading of the evidence for each of the 22 process areas and computes the maturity level the staged representation would give. It is not an appraisal, which is done by trained appraisers with the SEI's appraisal method; it shows how the staged rule works.

# CMMI for Development v1.3's 22 process areas by maturity level, and this book's reading of the
# evidence for ExamReg's software house from earlier chapters (True: practised; False: not yet)
LEVELS = {
    2: {"Requirements Management": True, "Project Planning": True,
        "Project Monitoring and Control": True, "Supplier Agreement Management": False,
        "Measurement and Analysis": True, "Process and Product Quality Assurance": True,
        "Configuration Management": True},
    3: {"Requirements Development": True, "Technical Solution": True, "Product Integration": True,
        "Verification": True, "Validation": True, "Organizational Process Focus": False,
        "Organizational Process Definition": False, "Organizational Training": False,
        "Integrated Project Management": False, "Risk Management": False,
        "Decision Analysis and Resolution": False},
    4: {"Organizational Process Performance": False, "Quantitative Project Management": False},
    5: {"Causal Analysis and Resolution": True, "Organizational Performance Management": False},
}

def staged_level(levels):
    """The highest maturity level whose process areas, and all those below it, are practised."""
    reached = 1
    for level in sorted(levels):
        if not all(levels[level].values()):
            break
        reached = level
    return reached

for level, areas in LEVELS.items():
    missing = [name for name, met in areas.items() if not met]
    print(f"level {level}: {len(areas) - len(missing)} of {len(areas)} practised;"
          f" missing: {', '.join(missing) or 'none'}")
print("maturity level reached (staged):", staged_level(LEVELS))
LEVELS[2]["Supplier Agreement Management"] = True        # an agreement with the gateway's provider
print("with a supplier agreement for the payment gateway:", staged_level(LEVELS))

level 2: 6 of 7 practised; missing: Supplier Agreement Management
level 3: 5 of 11 practised; missing: Organizational Process Focus, Organizational Process Definition, Organizational Training, Integrated Project Management, Risk Management, Decision Analysis and Resolution
level 4: 0 of 2 practised; missing: Organizational Process Performance, Quantitative Project Management
level 5: 1 of 2 practised; missing: Organizational Performance Management
maturity level reached (staged): 1
with a supplier agreement for the payment gateway: 2

The staged answer. The software house practises 6 of the 7 level 2 process areas, 5 of the 11 at level 3, and even causal analysis and resolution at level 5. Yet under the staged representation it is at maturity level 1, because one level 2 process area, supplier agreement management, is missing. That process area applies here: CMMI's scope covers acquiring "products, services, and product and service components that can be delivered to the project's customer or included in a product or service system", and the payment gateway is part of ExamReg's service. One agreement with the gateway's provider would move the house to level 2.

The continuous view. The same evidence, read process area by process area, shows a more capable organisation than its level suggests: strong verification, validation and quality assurance, a working improvement loop, and weaknesses in organisation-wide process definition, training and risk management. That is why CMMI offers both representations. The staged rating says what the house cannot yet claim; the process area profile says where to work.

The next step. CMMI's advice not to skip levels points the same way as Chapter Ninety-Four's reading of ISO's principles: the first fix is relationship management with the supplier, then the organisation-level processes of level 3.

Choosing a methodology

The methods of this module answer different questions, and the table is this book's summary of what the sources say each is for.

Three points guide the choice. Match the method to the problem: a defect rate that varies widely is a Six Sigma problem; a slow flow of work full of waiting is a lean one; an organisation where every project works differently is a CMMI one. Combine them: ASQ notes that the distinction between lean and Six Sigma "has blurred", and every method uses a PDCA-like cycle inside. And start small: the IDEAL model and PDCA both begin by diagnosing and trying before committing the whole organisation.

What it does not mean

Lean is not cutting people. It removes work that adds no value; ASQ even counts non-utilized talent among the wastes.

A maturity level is not a measure of product quality. Level 1 organisations "often produce products and services that work"; the level describes how predictably they do.

The staged level does not tell the whole story. ExamReg's house is level 1 on the staged scale with practices up to level 5; the continuous representation shows the profile.

No method is best for every problem. The choice depends on whether the problem is a change to test, variation, waste, or an organisation's whole way of working.

Quick revision

• Lean (ASQ): management practices to improve efficiency and effectiveness by eliminating waste; lean enterprise extends it along the value stream; Toyota's objective: eliminate waste and shorten lead times.
• Eight wastes (DOWNTIME): defects, overproduction, waiting, non-utilized talent, transportation, inventory, motion, extra-processing.
• Lean against Six Sigma (ASQ): waste reduction against variation reduction.
• CMMI (v1.3): 22 process areas; staged (maturity levels) and continuous (capability levels) representations; levels 1 Initial, 2 Managed, 3 Defined, 4 Quantitatively Managed, 5 Optimizing; do not skip levels; IDEAL: Initiating, Diagnosing, Establishing, Acting, Learning. Later versions (V2.0 and after) are kept by the CMMI Institute (ISACA).
• Choosing: fit the method to the problem; combine methods; start small.
• Worked example: ExamReg's house practises 6 of 7 level 2 areas, 5 of 11 at level 3 and 1 of 2 at level 5, but is level 1 staged, for lack of supplier agreement management; with an agreement for the payment gateway, level 2.

Test yourself

1. What is lean, and what are its eight wastes? A set of management practices to improve efficiency and effectiveness by eliminating waste, work that adds no value for the customer. The eight wastes, remembered as DOWNTIME, are defects, overproduction, waiting, non-utilized talent, transportation, inventory, motion and extra-processing.

2. Give software examples of three of the wastes. Defects: the rework of finding and fixing bugs, especially after release. Waiting: work stopped for a supplier, a review or an approval, like ExamReg's 72-hour wait for the payment gateway's provider. Overproduction: reports produced that nobody reads, like a coverage report for every module on every build.

3. Describe CMMI's five maturity levels. Level 1, Initial: processes are ad hoc and chaotic, and success depends on individual heroics. Level 2, Managed: projects plan and execute processes according to policy, and monitor and control them. Level 3, Defined: processes are described in organisation-wide standards and tailored for each project. Level 4, Quantitatively Managed: quantitative objectives for quality and process performance are used to manage projects. Level 5, Optimizing: processes are continually improved from a quantitative understanding of the organisation's objectives and performance.

4. Distinguish CMMI's staged and continuous representations. The staged representation rates an organisation on maturity levels, each requiring a set of process areas at that level and below. The continuous representation rates each process area separately on capability levels, giving a profile rather than a single number.

5. Why was ExamReg's software house at maturity level 1 despite practising causal analysis? Because the staged representation requires every process area of level 2 before level 2 is reached, and one, supplier agreement management, was missing: there was no agreement with the payment gateway's provider. Practices at higher levels do not count until the levels below are complete.

6. How should an organisation choose among PDCA, Six Sigma, lean and CMMI? By the problem: PDCA for a specific change to try and learn from; Six Sigma for too much variation or too many defects in a process; lean for too much waste, such as waiting and rework; CMMI for an organisation whose processes are ad hoc or inconsistent. The methods can be combined, and each change is best started small.