Fielding Systems-of-Systems, Riding the agile sw tiger

The Fourth National Conference
INCOSE_IL 2007

• Session: Integration – Unsolved Question
• Lecture Name: Fielding Systems-of-Systems
– Ride the Software Tiger
• Presented by Sergey Tozik

1 Integration-unsolved question
Fielding SoS – Ride the SW Tiger INCOSE_IL 2007

Outline
• Challenge:
Fielding of SW-intensive SoS

• Method:
Knowledge driven IVVT

• Technique:
Explorative Modeling


SoS: Complexity of Operation
Specify Operate Modify
Needs Systems

System Integrate

Capability

Capability
Capability

Capability
System

System
Test

SoS: Emergent Dependency
Project A Project B
independent
Capability A Capability B

Change Change No Change No Change Change
System 1 System 2 System 3 System 2 System 3

Reqs Reqs Reqs
System 1 System 2 System 3

Capability A dependent Capability B

SW Challenge
• Simple designs, Agile development
very short development
• Interdependence of systems 
abundance of surprises 
very long fielding times
• Challenge for integrators & testers:
hang for your life and still deliver


Hang for Your
life, dear…
It’s AGILE !!!!


What Users Want?
1. More Mission Capabilities

2. Easier Operation

3. No Surprises


Elements of Solution
• Focus on “Knowledge Creation”
instead of “Test against Spec”

• Hunt for unintended consequences

• Know what works and field it!


MaSK Methodology

• Explorative Modeling

• Semi-automatic test generation

• Session-based testing

• Knowledge factory concept


Integration Engineer Roles
Information

Information Gatherer Tester

Directions of Inquire Test Ideas

Analyst

Knowledge

Stakeholder

• Information Gatherer searches the sources for
information and clues about past and supposed behavior
• Tester creates and executes tests to capture information
about actual behavior
• Analyst directs the gatherers, creates knowledge and
morphs it to stakeholders’ needs

Knowledge Generation Steps
1. Gather Initial Batch of Information
2. Analyze Information
3. Create Knowledge
4. Detect Knowledge Gaps
5. Direct the Hunters for more Info
6. Gather More Information
7. Go to Step 2
Never Stop Asking Questions!


Sources of Information
1. Users’ Manuals
2. Requirements
3. Design Documentation
4. Interface Control Documents
5. Test Results
6. Interviews of Developers
7. Interviews of Users

The Knowledge Factory Workflow
Gather Info Info Create/Refine Models

Info
Hunting Use Model Technical Model
Loop

1..N 1..N
Question Analyse Models Insight

1..N
Knowledge
1..N Tests
Refinement
Stakeholder Loop
Value Loop
Plan, Execute Tests
Customer

Testing
Publish Loop
Test Results

1..N
Report Analyse Test Results


Explorative Modeling
1. Motivation: technique for fast learning
with limited domain expertise
2. Language: Cause-Effect Graphs
3. Use Models captures Business Processes in
Users’ Language
4. Technical Models capture Design
Information in Developers’ Language


Have You a SPEC?
Explorative No?!!
Modeling
Tool
I beg You,
Not Again!!!!


Basic link in Cause-Effect Graph
Data, Matter, E Data, Matter,
nergy Energy

Trigger

Output Entity
Input Entity
Processing
Event

Pre-Contition
Post-Condition
System Event
Environment causes changes in
State system/environment Environment
State

Knowledge Gaps Discovery

1. Not enough information to complete
Use Model
2. Not enough information to understand
processes initiated by System Event
3. Inconsistencies in information sources
4. Developer’s insecurity (Oops factor)


Example – Story of Two Cities
• Two neighbor cities

• Each city has Traffic Light Control System (TLCS)

• Every TLCS has manual and automatic modes

• Each TLCS did the job well until some day suddenly
the effectiveness of the AUTO mode have dropped.

• Why?

• We’ll try to generate clues using Exploratory
Modeling technique

Use Model
Focus: visible system behavior, user actions
Identify System Events (Identify Trigger)
• Set System to Manual (User)
• Set System to Automatic (User)
• Change Single Traffic Light Mode (User)
• Change Traffic Light Pattern (System, Periodic)
• Respond to Traffic Light Pattern (Natural)
Connect Events with I/O Entities/Conditions 
Build Cause-Effect Graph

Cause-Effect Graph
Nothing happens without a reason!

Manual Respond to
Traffic Lights
Mutual
Influence
Respond to
Traffic Lights
Feedback City A
Traffic Pattern City B
Loop Traffic Pattern
Auto
Feedback Auto
Loop Feedback
City A
Loop
Traffic Light Pattern System B
System A
Generate Traffic Cycle Clock Cycle Clock
Light Pattern - City A
City B
Generate Traffic Traffic Light Pattern
Light Pattern - City B
Periodic
Change Activation
Traffic Light Change
Traffic Light
Disable when AUTO
Display Traffic
Disable when AUTO Pattern
Display Traffic
Pattern

System A System B
Auto/Man Auto/Man Set to MANUAL
Set to MANUAL

Operator City B
Operator City A
Set to AUTO Transient Set to AUTO
Generator


Directions for Inquiry
1. Analyze mutual influence and concurrency
of automatic control feedback loops
2. Analyze mutual influence and concurrency
of manual control feedback loops
3. Analyze mutual influence of automatic and
manual feedback loops
4. Analyze concurrency of AUTO/MANUAL
transients


Direct Test Case Derivation
1. Identify EVENT

2. Prepare INPUT ENTITYs for the EVENT

3. Set INPUT CONDITIONs for the EVENT

4. Initiate EVENT

5. Verify OUTPUT ENTITYs

6. Verify OUTPUT CONDITIONs


5-Step Test Cycle
1. Design Initial Test Event

2. Execute Initial Test Event, Gather Data

3. Analyze Data, Identify Knowledge Gaps

4. Execute Investigative Test, Gather Data

5. Analyze Data, Draw Conclusions, Report


Technical Models
• Motivation: enrich understanding
of System Events
• Analysis of cause-effect chains
triggered by System Events
• Utilize developers’ expertise
• Discover missing conditions and entities
• Technique: anything useful!

What’s Next?
• Enrich Technical Analysis
• Discover appropriate CAD tools
• Add Simulation Capabilities
• Add Knowledge Management Tools
• Evaluate utility of Systems Theory


Summary

• SW + SoS = the real challenge
• Methodology: Knowledge Factory
• Techniques: Explorative Modeling
• There’s still a lot to learn
to ride the tiger and survive!


Fielding Systems-of-Systems, Riding the agile sw tiger

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