1. How Systems are Developed
The Commercial Life Cycle Model
Common form of the Software Life Cycle
Used through the commercial, industrial, institutional
government communities
University of Houston Clear Lake
Natural and Applied Science
James C. Helm, Ph.D.,P.E.

3. Example Software Development Process
This process illustrates the major steps and flow that might be typical of a DoD or major Government Contractor.
The documents would be obtained from the DoD standard, MIL-STDs, or IEEE
NASA Software Document Standard, Software Engineering Program, NASA-STD

4. Example Software Development Process
Completed
Software
System
Requirements
Analysis A B
Engineering
Change
Control
Formal
SCCB C
Example Software Development Process RR
Allocated
Baseline
HDR
IDR
Architecture
Design
Interface
Verification
and
Validation
Test D
Data
Structure
Algorithm
Coding
Unit
Testing
Component
ENGINEERING BUILD
Configuration
Item
Management
Load Build
Product
TPR
SCM
Release
Dr Jim Helm
Metric
Point
Dictionary
Cases
DataBase
Informal
Test Data
PDL
Flowchart
Package or
Declaration
SOFTWARE
REQUIREMENTS
ANALYSIS
PRELIMINARY
DESIGN
DETAILED
CODE
CSU / CSC
INTEGRATION
TEST
CSCI
BLOCK TEST
VALIDATION TEST
Requirements Analysis
Object Oriented Analysis
Content Diagram
Bound Limits
Information Modeling
Object Flow Diagram
Object Specification
State Transition Diagrams
Structured Walkthroughs
Requirements Comments
Report
Object Oriented Design
Object Reuse
Design Specification
Decision Tables
Object Activation Tables
Prototypes
Superior Refinement
Structured Walkthrough
Update Prototype
Update Preliminary Desing
into Test Case Design
Structured Programming
Package Reuse
Structured Codes Walkthrough
Structured Test Walkthrough
Update Software
Development Folders
Update Requirements Matrix
Execute White Box Testing
Execute Black Box Testing
Review Test Results
CSU Integration
Top-Down
Bottom-Up
Sandwich
Code / Test data Walkthrough
Execute Interface Tests
Execute Black Box Tests
Development Folder
Update Requirements Matrix
Execute Regression Tests
CSCI Integration
Test / Requirements Metrix
Test Walkthrough
Formal Test Execution
Test Results Review
Final Test Results
CSCI Verification
Formal Test Case
Test Procedures
Software Validation Test Reports

5. Requirement Phase Deals with all kinds of requirements system software
hardware
human system Interface
human in the loop

7. Design Phase Normally consists of two parts Preliminary Design
Detailed Design

9. Code Phase Implements the detailed design
Some form of programming language
Three possible coding options
top-down
bottom-up
middle-out

10. Develop Large
Driver to
Stimulate System
Establish/
Retain
Required
Databases
TOP-DOWN
Code Top Level
CSC Then Next
Level, etc.
Final
Integration
is minimal
Select
Appropriate
Compiler/
Assembler
Test Whole
System
Each Time
OPTION 1
Select
Appropriate
Programming
Support Environment
Develop Several
Drivers to Stimulate
Subsystems
Code CSCs
as functional
threads
Integration
is moderate
throughout
Test Each
Functional
Thread
MIDDLE-OUT
OPTION 2
Determine
Optimum
Coding Strategy
& Sequence
Ready
for
I & t
FROM DESIGN PHASE
Initiate
Appropriate
Controls
Follow
Standards &
Conventions
OPTION 3
Develop many
drivers to
Stimulate CSUs
Establish
Software
Library
BOTTOM-UP
Code CSUs
separately
Integration is
Time Consuming
Test Each
CSU
Extensively

11. Correlation Between Specifications and Test
Match the kind of software being developed and the manner in which it is being implemented and integrated
Specification hierarchy
Test hierarchy

13. Integration and Testing Phase
Major Activities shown on next slide
Determine early the selection and specification of the optimum test strategy
Select: tools, instrumentation, recording methods and SW drivers
Select environment: hardware configuration and location of tests