Software Process Improvement

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Software Process Improvement
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SPIN

• Software Process Improvement Network
• http//www.sei.cmu.edu/collaborating/spins/spins.h
  tml
• SEI - Software Engineering Institute
• Managing the Software Process - Watts Humphrey

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Keys to a project

• People
• Product
• Process

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How do you improve your process?

• Understand it
• Decide something needs to be improved
• Make a plan to improve it
• Execute the plan
• Evaluate results

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Principles of Change

• Major changes to the software process start at
  the top
• Ultimately, everyone must be involved
• Must have a goal and know current process
• Change is continuous
• Changes will not be retained without effort and
  reinforcement
• Process improvement is an investment

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Stages of change

• Installation
• Learning the basics
• Practice
• Proficiency
• Becoming good enough to be successful
• Naturalness
• No longer thinking about it

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Stages of change

• All change is disruptive
• Until you are proficient, performance is worse
  than before
• Dont decide whether change is good until people
  have a chance to become proficient

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Change is disruptive

• Dont make too many changes at once
• Dont punish failure
• A change that is good for me might not be good
  for you
• A change that is easy for me might not be easy
  for you

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Effort to improve the process

• Someone must evaluate, decide, plan
• Manager
• XP coach
• Process improvement team
• Make small changes and test them
• Train!

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Capability Maturity Model

• CMM describes the practices of an organization at
  a particular level.
• Can be used to
• Guide process improvement
• Assess software process capability
• Provides an orderly framework in which to do good
  engineering
• Describes what an organization should be
  practicing

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CMM Maturity Levels

• 5 Optimizing Continuous process improv.
• 4 Managed Product and process quality
• 3 Defined Engineering Process
• 2 Repeatable Project Management
• 1 Chaotic

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Level 2 - Repeatable

• Requirements management
• Software project planning
• Software project tracking
• Software subcontract management
• Software quality assurance
• Software configuration management

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SQA

• Monitors product quality and adherence to plan
• Monitors process quality and adherence to plan
• Does not ASSURE quality
• Developers create quality
• Managers make tough decisions about quality

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SQA

• In small groups, performed by manager and/or by
  entire team
• In large groups (maybe gt20, certainly gt50),
  performed by SQA team
• Testers often considered part of SQA team

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IVV

• Independent verification and validation
• Checks on work of subcontractors
• Testers that work for your customer
• SQA works for the producing organization

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Level 3 - Defined

• Organization process focus
• Organization process definition
• Peer reviews, testing, SCM plans
• Training program
• Integrated software management
• Software product engineering
• Intergroup coordination

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Level 4 - Managed

• Quantitative process management
• Process metrics
• Software quality management
• Product metrics

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Level 5 - Optimizing

• Defect prevention
• Technology change management
• Process change management

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Optimizing

• Periodically look at the data
• What are our biggest problems?
• How could we solve them?
• How much would that cost? Is the benefit worth
  the cost?
• How are we going to implement this change?

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Optimizing

• Happens on many levels
• Managers optimize the whole process
• Each developer optimizes his own job
• Each developer optimizes work of team
• Managers/SQA meet to review entire project
• Design/Code reviews review products and make
  suggestions

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Optimizing

• Collect data
• Store all bug reports in a database
• Analyze data
• What is the cause of each bug? What category
  causes the most bugs? What could we do to
  prevent that bug?
• Make a plan for improvement
• Implement the plan

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Slogans for Designing a Process

• Productivity is correlated with being in control.
• Design your own process
• Having a standard is more important than which
  standard
• Everyone must agree to it

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Slogans for Designing a Process

• If it isnt broken, dont fix it.
• Dont make a change unless people are
  dissatisfied.
• Kick the nearest wolf from the door.
• Change one thing at a time. Pick the worst
  problem and try to solve it.

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How to get ideas for improvement

• Magazines
• Mailing lists, web pages
• Local groups (SPIN, ACM, Java user group)
• External consultant
• Internal consultant

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How to get ideas

• Every group needs someone who is outwardly
  focused, who brings in new ideas.
• A good manager periodically brings in an outsider
  for a review
• Hire young people from UIUC

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Software Process Improvement

• Must know what is happening now
• Requires data
• Requires management commitment to change
• Change is expensive!
• Change can be valuable
• Continuous small changes are better than
  irregular big changes