tyutyunnick pavel ([email protected]), stefan puchner...

Tyutyunnick Pavel ([email protected]), Stefan Puchner ([email protected])

Steklov Institute St. Petersburg, Technical University München

JASS 2006

Advanced Topics in Software Engineering

Rationale Management

2 JASS 2006 (02.-12.04.2006) - Rationale Management

Motivation

Example:

Slicing Ham


What is Rationale Management?

• RationaleJustification for decisions

• Rationale ManagementCapture and organize rationales in

• Problem• Possible solutions• Arguments• Criteria• Decision

• Other models tell how – rationale tells why


Why Rationale Management? (I)

• Improves Decision making process:– Explicitly splits decision making process into its

elements (criteria, priorities, …)– Therefore enables more educated decisions

• Makes later changes easier and safer:– Captures knowledge that is not included elsewhere and

makes it reusable– Reminds developers of requirements that need to be

considered


Why Rationale Management? (II)

• Helps new developers– Keeps the reasoning reproducible and comprehensible

for third persons– Explains why the model is as it is

• Problems– Big investment for gathering and maintaining additional

information– Rationale models get very large


Transfer Question

Example:

Cookbook


Elements of a rationale

• Issueunsolved question

• Proposalpossible solutions to issue

• Criterionqualities proposals should have

• Argumentdiscussion for/against proposalssupported by criteria

• Resolutionselected solution to issue


Representation of rationales - example

storage?:Issue

database:Proposal

storage in database:Resolution

files:Proposal

which Database?:Issue

flexibility$:Criterion simplicity$:Criterion

extensibility-first:Argument

addressed by

resolves

addressed by

fails fails

meets meets

is supported by

is opposed by

raises


Where can rationales be captured?

• Requirements analysisUseful for developing test cases

• System designLinks nonfunctional requirements to design goals (important if requirements change)

• Project managementDocuments alternatives and risks, can provide fallback solutions

• Integration and testingDetermine which decision created conflict


Levels of rationale capture

• No explicit rationale captureRationale in E-mails, memos, memories …

• Rationale reconstructionCapture rationale afterwards / less detail

• Rationale captureRationale model besides other models

• Rationale integrationRationale is central model


Capturing Rationale Activities

• MeetingsTake minutes, decompose into elements of rationales

• Electronic communicationIntegrate rationale model into groupware

• ChangesAdapt rationale model, new resolutions

• Reconstructing rationaleConstruction of rationale model based on memory and actual system model


Managing rationale

Rationale management hardly used in industry– Additional effort– No direct connection between effort and benefit

subject for management

• Include rational model in development tools• Assign Responsibilities

– Minute taker– Rationale editor– Reviewer


Summary

Capturing rationale model is– great effort but has– huge benefits

Goal:

Improvements in capturing and maintaining rationales to make rational management more common


Conservative view & optimization

• The major goals of management• Traditional management models• Difference between models• Optimization examples• Rational management implementation

Rational models integration experience


Questions ?

Source:

B. Bruegge & A. Dutoit.Object-Oriented Software Engineering(Second edition, International edition)

Pearson Prentice Hall, 2004.