Two Case Studies
•
•
•
•
•
CCPDS-R, TRW
How Microsoft Builds Software
Different development environments
Software development life cycle
Software project management
techniques
CCPDS-R Case Study
• Command Center Processing and
Display System – Replacement
• TRW Space and Defense in Redondo
Beach, CA
• Customer : U.S. Air Force
• Focus : Common Subsystem
• Mission critical software
Common Subsystem
• Primary missile warning system
• Main installation : Cheyenne Mountain
• Backup system : Offutt Air Force Base,
Nebraska
• 48-month software development schedule
• 355,000 SLOC
• Ada : design & implementation language
• 6 builds were required
• Completed successfully, on time within
budget to customer satisfaction
CCPDS-R Acquisition
• Concept definition (CD), 12-month
schedule
• 5 major bidders, 2 contracts awarded
• Full-scale development (FSD)
• 1 contract awarded to TRW
• Contract award based on
performance in Software Engineering
Exercise
Concept Definition (CD)
•
•
•
•
Vision
Analyze and specify the project requirements
Define and develop the top-level architecture
Plan FSD phase software development
activities
• Configure the process and development
environment
• Establish trust and win-win relationships
among the stakeholders
• Software engineering exercise
Process Overview for FSD
• Standard DOD life cycle after
contract award
• Software requirements review (SRR)
• Interim preliminary design review
(IPDR)
• Preliminary design review (PDR)
• Critical design review (CDR)
• Final qualification test (FQT)
Incremental Design Process
•
•
•
•
•
Individual milestones within a build
Preliminary design walkthrough
Critical design walkthrough
Code walkthrough
Turnover review
Incremental Test Process
• Stand-alone test
• Build integration test; establish a
stable, reliable baseline
• Reliability test
• Engineering string test
• Final qualification test
IPDR Demonstration
• Demonstrate defined capabilities at NORAD
• Capabilities well understood by the
customer and TRW
• 37 evaluation criteria
• Results were apt to change requirements,
plans and designs
• 31 satisfactory, 6 were not met
• Required redesign and re-demonstration
Metrics
•
•
•
•
Build Progress (% coded) vs time
Requirements verified vs time
Cumulative SLOC vs time
Average hours per software change
order (SCO)
• Mean time between failure (MTBF) vs
total test hours
• Cumulative SLOC vs budget
People factors
• Core team concept
• Leverage skills of a few experts
across the entire team
• Avoid attrition
• Profit sharing of award fees
Microsoft Case Study
• High volume, mass market software
• Redmond, Washington
• Excel, Word, Windows 95, Windows
NT, etc.
• Respond to events in the
marketplace
• Highly flexible, entrepreneurial
company
Microsoft Competitive
Strategy
• Identify mass markets quickly
• Introduce products that are “good
enough”
• Improve products by incrementally
evolving their features
• Sell multiple product versions and
upgrades
• Sell globally
Product Development
Philosophy
• Utilize small parallel teams (3 to 8
developers)
• Teams evolve features and products
incrementally
• Occasionally introduce new concepts and
technologies
• Synchronize changes frequently so product
components work together
• Structured hacker-like approach
Synch-and-Stabilize
• Continually synchronize what developers
are doing as individuals and team members
• Stabilize the product in increments
• Daily build
• Continual testing
• Testers work in parallel with developers (1
to 1)
• Fix defect immediately if checked in code
“breaks” the daily build
Big Picture Procedures
• Teams work at single physical site
• Common development languages (C
and C++)
• Common coding styles
• Standardized development tools
• Teams must communicate, debate
design ideas, and resolve problems
face to face
Synch-and-Stabilize
Development Approach
• Planning Phase
• Development Phase
• Stabilization Phase
Planning Phase
• Vision statement
• Product managers define goals for a new
product based on market research
• Specification document written up by
Program manager
• During development, feature set in
specification document may change by
30% or more
• Schedule and feature team formation
Development Phase
• Developers design, code, and debug
• Testers pair with developers for continuous
testing
• 3 major milestones
• Milestone 1 : first 1/3 of features (most
critical and shared components)
• Milestone 2 : second third of features
• Milestone 3 : final third of features (least
critical)
Stabilization Phase
• Internal testing
• External testing (“beta” sites
and users)
• Release preparation
Principles – Developing and
Shipping Products
• Work in parallel teams but “synch up” and
debug daily
• Always have a product you can ship, with
versions for different platforms and markets
• Speak a “common language” on a single
development site
• Continuously test the product as you build it
• Use metric data to determine milestone
completion and product release
Conclusions
• Stakeholders and type of software being
developed effect the software development
life cycle
• CCPDS-R - more externally controlled
process
• Microsoft – market driven – internally
controlled process geared towards
customer satisfaction and market share
• Both cases illustrate extensive use of
modern software project management
techniques
• Both cases show level 3 (defined) of CMM