October 16, 2015 – 16:09:421 © 2006 University of California, Irvine – André van der Hoek Examining Software Design From A General Design Perspective Alex

© 2006 University of California, Irvine – André van der HoekApril 20, 2023 – 00:30:41 1

Examining Software Design From A General Design Perspective

Examining Software Design From A General Design Perspective

Alex Baker and André van der HoekDepartment of Informatics

Donald Bren School of Information and Computer Sciences

University of California, Irvine

{abaker,andre}@ics.uci.edu

© 2006 University of California, Irvine – André van der Hoek 2April 20, 2023 – 00:30:41

“Just” Some Questions“Just” Some Questions

What is a good notation for software design?



What is a good notation for software design? What constitutes a good software design?



What is a good notation for software design? What constitutes a good software design? What is a good approach to design?



What is a good notation for software design? What constitutes a good software design? What is a good approach to design? What makes one a good designer?



What is a good notation for software design? What constitutes a good software design? What is a good approach to design? What makes one a good designer? What factors influence design?



What is a good notation for software design? What constitutes a good software design? What is a good approach to design? What makes one a good designer? What factors influence design? What is software design?


Some Answers: AgileSome Answers: Agile

What is a good notation for software design?– code

What constitutes a good software design?– code fully refactored

What is a good approach to design?– architect some beforehand– build, test, refactor throughout

What makes one a good designer?– experience, pair programming

What factors influence design?– programming language, tools, designers

What is software design?– “the design is in the code”


Some Answers: Strict WaterfallSome Answers: Strict Waterfall

What is a good notation for software design?– any

What constitutes a good software design?– complete and consistent

What is a good approach to design?– transform and verify requirements

What makes one a good designer?– knowledge

What factors influence design?– requirements, methodology

What is software design?– “design is a transformational phase in the software

life cycle”


Some Answers: IncrementalSome Answers: Incremental

What is a good notation for software design?– any

What constitutes a good software design?– extensible (in the right way)

What is a good approach to design?– create a core architecture, keep it synchronized with

the code, and update each iteration What makes one a good designer?

– domain knowledge, experience What factors influence design?

– feedback from users, ability to update architecture What is software design?

– “design is an up-to-date roadmap”


Typical ReactionsTypical Reactions

Which one is true? Which one is better? Which one should we follow? …


Typical ReactionsTypical Reactions

Which one is true? Which one is better? Which one should we follow? …

These are the wrong questions, generally leading tobitter discussions based on beliefs, not on grounded facts


The ProblemThe Problem

What is a good notation for software design? What constitutes a good software design? What is a good approach to design? What makes one a good designer? What factors influence design? What is software design?

To date, the community lacks a common understanding fromwhich to answer these, and other, questions of software design


ApproachApproach

1. Step outside of software design2. Examine other design disciplines3. Examine general design literature4. Bring together the lessons learned in a

generic framework of design5. Apply the framework to software design


Step 1: Step Outside of Software DesignStep 1: Step Outside of Software Design

We make no assumptions as to what software design is supposed to be– phase– document– creative– precise– consistent– object oriented– …

In essence, we temporarily forget everything we have learned about software design


Step 2: Examine Other Design DisciplinesStep 2: Examine Other Design Disciplines

Read, read, read, …– The Timeless Way of Building [Alexander]– The Design of Everyday Things [Norman]– The Art of Innovation [Kelley]– …

Learn what are important perspectives and important factors in other disciplines– freedom of expression– multiple representations– communication– iteration– …


Step 3: Examine General Design LiteratureStep 3: Examine General Design Literature

Read, read, read, …– The Sciences of the Artificial [Simon]– Design Methods [Jones]– The Reflective Practitioner: How Professionals Think

in Action [Schön]– Grounding in Communication [Clark and Brennan]– …

Learn what are important general principles– design spaces– divergence, transformation, convergence– reflective conversation with materials– communication– …


Step 4: Bring Together the Lessons Learned in a Generic Framework of DesignStep 4: Bring Together the Lessons Learned in a Generic Framework of Design

Try, try, try, …– Eyeglass– Design Diamond– Product / Process


EyeglassEyeglass


Eyeglass – ProblemsEyeglass – Problems

Inconsistent meaning of “contains”,does not capture everything, still ambiguity


Design DiamondDesign Diamond

Goal

Domain of Materials

Representation

Domain of Use

Knowledge

ActivityIdeas

concern

manipulatesinformscapturesenhances


Design Diamond – ProblemsDesign Diamond – Problems

Goal

Domain of Materials

Representation

Domain of Use

Knowledge

ActivityIdeas

concern

manipulatesinformscapturesenhances

Complicated, missing links,difficulty of separating dimensions


Product / ProcessProduct / Process

designer project customer

outcomes

design space

CD

CCDF SP

activity

goal (lang) knowledge (lang)

ideas (lang) representation (lang)

tools


Product / Process – ProblemsProduct / Process – Problems

Thus far – none (but your feedback is much desired)


outcomes

design space

CD

CCDF SP

activity



tools


ProductProduct


outcomes

design space

CD

CC

DF SP

A state represents one design product, which is defined asan abstraction that constrains the set of still possible outcomes

C = conceivableF = feasibleD = desirableSP = still possible


ProductProduct


outcomes

design space

CD

CC

DF

A successful design product restricts the set of still possibleoutcomes to those that are feasible and desirable

D


ProcessProcess

activity



tools

The design process is characterized as one ofinformation manipulation


Teams, Stakeholders, and CommunityTeams, Stakeholders, and Community

representation (lang)

goal (lang)

activity


ideas (lang)

tools

activity

knowledge (lang)

ideas (lang)

tools

Information exchange among multiple people takes placeas communication through a shared representation


A Quick ScenarioA Quick Scenario


outcomes

design space

CD

CCDF SP

activity



tools




outcomes

design space

CD

CCDF SP

activity



tools




outcomes

design space

CD

CCDF SP

activity



tools




outcomes

design space

CD

CCDF SP

activity



tools




outcomes

design space

CD

CCDF SP

activity



tools




outcomes

design space

CD

CCDF

SP

activity



tools



designer customer

outcomes

design space

CD

CDF

activity



tools

project

CSP



designer customer

outcomes

design space

CD

CDF

activity



tools

project

CSP




outcomes

design space

CD

CCDF SP

activity



tools



designer customer

outcomes

design space

CD

CDF

activity



tools

project

CD SP



designer customer

outcomes

design space

CD

CDF

activity



tools

project

CSP



designer customer

outcomes

design space

CD

CDF

activity



tools

project

CSP


A Generic Perspective on DesignA Generic Perspective on Design


outcomes

design space

CD

CCDF SP

activity



tools

Every discipline must address the same product, process,and communication factors, in a manner suitable to its domain


TensionsTensions

A goal constrains desirable outcomes A goal guides generation of ideas Knowledge informs outcome feasibility Knowledge informs outcome desirability Knowledge guides generation/evaluation of

ideas Knowledge guides creation of representations Ideas constrain still possible outcomes Ideas shift goals Ideas build knowledge Representations record personalized

information Representations communicate information


TensionsTensions


outcomes

design space

CD

CCDF SP

activity



tools


TensionsTensions


outcomes

design space

CD

CCDF SP

activity



tools


TensionsTensions


outcomes

design space

CD

CCDF SP

activity



tools


TensionsTensions


outcomes

design space

CD

CCDF SP

activity



tools


TensionsTensions


outcomes

design space

CD

CCDF SP

activity



tools


Step 5: Apply the Framework to Software DesignStep 5: Apply the Framework to Software Design

Understanding unique nature of software Comparing high-level approaches Judging individual contributions Suggesting new research directions


CD

C

Understanding Unique Nature of Software #1Understanding Unique Nature of Software #1


outcomes

design space

CDF SP

activity



tools

Large space of feasibility


FC

Foutcomes



design space

CD

CD SP

activity



tools

Goal specificity


FC

Foutcomes



design space

CD

CD SP

activity



tools

Language gap


Impact of Our FrameworkImpact of Our Framework

Help understand the difficulties inherent to software design– theoretically deducted– empirically related to existing opinions (e.g., Brooks)

Begin to suggest ways in which we need to address them


Comparing High-Level ApproachesComparing High-Level Approaches

Agile Strict waterfall Incremental …


FC

FC

DC

D SP

TensionsTensions


outcomes

design space

activity



tools


FC

Foutcomes

Unique Nature of Software #1, #2, #3Unique Nature of Software #1, #2, #3


design space

CD

CD SP

activity



tools


CDF

CF

CD SP

AgileAgile


outcomes

design space

activity



tools

“The design is the code”


CSPF

CF

outcomes



design space

CD

D

activity



tools

“The design is the code”


FC

F DC

DC

SP

WaterfallWaterfall


outcomes

design space

activity



tools

“Design is a transformational phase in the software life cycle”


FC

Foutcomes



design space

CD

CD SP

activity



tools

“Design is a transformational phase in the software life cycle”


CSPF

CF

CD

D

IncrementalIncremental


outcomes

design space

activity



tools

“Design is an up-to-date roadmap”


CSP

CDF

CF

outcomes



design space

D

activity



tools

“Design is an up-to-date roadmap”



Help understand the choices that different points of view make– what are the resulting design strengths– what are the resulting design weaknesses

Move community from arguments rooted in opinion to arguments based on a sound, shared framework– “force the hand”


Judging Individual ContributionsJudging Individual Contributions

(will not do here)


FC

FC

DC

D SP

Suggesting New Research DirectionsSuggesting New Research Directions


outcomes

design space

activity



tools


FC

Foutcomes



design space

CD

CD SP

activity



tools


FC

Foutcomes

Research Direction #1: SubdomainsResearch Direction #1: Subdomains


design space

CD

CD SP

activity



tools


CF

outcomes

Research Direction #2: Software AestheticsResearch Direction #2: Software Aesthetics


design space

CD

CSP

activity



toolsD


FC

FC

DC

D SP

Research Direction #3: Imprecise LanguagesResearch Direction #3: Imprecise Languages


outcomes

design space

activity



tools


CSPF

CF

CD

D

Research Direction #4: Become Involved in the Design of Programming Languages

Research Direction #4: Become Involved in the Design of Programming Languages


outcomes

design space

activity



tools


FC

FC

DC

D SP

Research Direction #5: Real-time Integrated FeedbackResearch Direction #5: Real-time Integrated Feedback


outcomes

design space

activity



tools


FC

FC

DC

D SP

Research Direction #6: Face-to-Face Design Collaboration Research Direction #6: Face-to-Face Design Collaboration


outcomes

design space

activity



tools


Research Direction #6: Face-to-Face Design CollaborationResearch Direction #6: Face-to-Face Design Collaboration


Research Direction #6: Face-to-Face Design CollaborationResearch Direction #6: Face-to-Face Design Collaboration



Knowledge– sub-domains – software aesthetics

Language– imprecise languages– become involved in the design of programming

languages

Tools– real-time integrated feedback– face-to-face design collaboration



Help identify new research directions through principled exploration of the framework

Help identify where research directions help and where they hinder– immediately understand the tradeoffs

Help distinguish “good” research plans from “bad” research plans


ConclusionsConclusions

The field of software design has long made do without a shared understanding of what is software design– problematic– stifling

We have presented a novel, generic framework of design and applied it to software design

Not mentioned: education This is work in progress

– any and all feedback is appreciated

Documents

October 16, 2015 – 16:09:421 © 2006 University of California, Irvine – André van der Hoek Examining Software Design From A General Design Perspective Alex