Process Improvement
CMM
Hans Van Vliet, Software Engineering, Principles and Practice,
3rd edition, John Wiley & Sons, 2008. Chapter 6.
W. Humphrey, Characterizing the Software Process: A Maturity
Framework. IEEE Software, 5(2):73-79, Mar 1988.
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Learning Objectives
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To know what process improvement is along
with its motivation
To understand CMM as an example process
improvement model
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Motivation
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Definition: Process Improvement
A series of actions taken to identify, analyze and
improve existing processes to meet new goals
and objectives, etc.

Why PI?
 Goal
of S/W development
=> To produce high-quality software
 Accomplish it by improving its process?
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Basic Model of Improvement
Observe some difficulty
 Collect some data
 Identify the root causes (hypothesis)
 Develop reasonable solutions (test)
 Plan and implement the changes
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Emphasis
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High-quality software
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correctness
reliability
robustness
user friendliness
verifiability
maintainability
safety
Finite amount of resources
Cost-effective manner
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Main cost in software is time
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Why is Process Improvement Difficult?

Software is variable:
 Processes
 Goals
 Content

Software development is:
 Evolutionary
and experimental
 Not production
 Human based

Lack of models:
 Needed
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to reason about the process and the product
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Process Improvement Framework Quagmire
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Capability Maturity Model (CMM)
for Software

Process capability
 Ability

of a process to produce planned results
Software Engineering Institute (SEI)
 Carnegie
Mellon
5 Levels: Levels 1-5
 Certification based on audits

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5 Stages of CMM for Software
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Level 1: Initial
Level 2: Repeatable
Level 3: Defined
Level 4: Managed
Level 5: Optimizing
Optimizing
Managed
Defined
Repeatable
Initial
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Capability Maturity Model
Level 5: Optimizing
Major improvements
in quality and quantity
Level 4: Managed
• Substantial quality improvements
• Comprehensive measurements
Level 3: Defined
Achieved foundation for major and
continuing progress
Level 2: Repeatable
Achieved a stable process with a
repeatable level of statistical control
Continuous process
Improvement
Quantitative
management
Process
standardization
Basic project
management
Level 1: Initial
• Ad hoc
• No process in place
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Heroics
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Group Work: CMM Levels

Read p. 137-142 or [Humphrey88]
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Team 1: Levels 1 & 2
Team 2: Levels 2 & 3
Team 3: Levels 3 & 4
Team 4: Levels 4 & 5
Team 5: Levels 1 & 2
Team 6: Levels 2 & 3
Study CMM levels focusing on
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Characteristics of each level
What should be done to move to the next level
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CMM Maturity Level 1: Initial
Characteristics
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No sound SE management
principles in place
Ad hoc practices
May be successful because of
competent manager and team
Activities are not preplanned,
but response to crisis
Unpredictable process
Cannot predict time and cost of
development
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To get to next level

Initiate project
management
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CMM Maturity Level 2: Repeatable
Characteristics
 Basic SE management
practices in place
 Planning and management
are based on experience
with similar products
(repeatable)
 Track costs and schedules
 Identify problems as arise
and take immediate
corrective action
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To get to next level
 Standardize
Processes
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Process Standardization
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Peer Reviews
Project Interface Coordination
Software Product Engineering
 methods
and technologies
 software development process architecture
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Integrated Software Management
Organization-level Awareness
 Organization
Training Program
 Organization Process Definition
 Organization Process Focus
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CMM Maturity Level 3: Defined
Characteristics
 Process for development
fully documented
 Reviews used to achieve
software quality
 Introduce CASE Tools
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To get to next level
 Quantitative Management
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Quantitative Management

Statistical process management
 quantify
quality and cost parameters
Process database to maintain process
data
 Assess relative quality of each product
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CMM Maturity Level 4: Managed
Characteristics
 Organization sets quality
and productivity goals for
each project
 Continually measure
 Statistical quality control
in place
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To get to next level
 Support automatic
gathering of process data
 Use data to analyze and
modify the process
 Defect Prevention
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CMM Maturity Level 5: Optimizing
Characteristics
 Statistical quality and
process control
techniques are used and
guide the organization
 Process has positive
feedback loop
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To maintain level
 Continue improvement
and optimization of the
process
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