design patterns

Design Patterns

Christophe Van [email protected]

mailto:[email protected]

Design Patterns

Christophe Van [email protected]

For

Analysts


Who Am I ?

• Christophe Van Ginneken

• Independent Software Architect

• Amateur Cook

• Catamaran Sailer

Who Are You ?• Employees of CTG

• Analysts or interested in analysis

• With or without technical background

• Using UML or not

• Writing Word documents or not

• An old school mate (Hi Britt)

• An ex-colleague (Hi Ron)

Ceci n’est pas ...• large list of design patterns

☞ http://themodelfactory.org

• focus on applying technical design patterns☞

• make you a CDPM (Certified Design Pattern Master)

☞ wake up !

http://themodelfactory.org/

Today’s Specials

• What are Design Patterns ?

• Why are they Important ?

• Why are they Important for Analysts ?

But first ...

What are Design Patterns ?

The Bible

Definition“Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice.”

Christopher Alexander


(born October 4, 1936 in Vienna, Austria) is an architect noted for his theories about design, and for more than 200 building projects in California, Japan, Mexico and around the world. Reasoning that users know more about the buildings they need than any architect could, he produced and validated (in collaboration with Sarah Ishikawa and Murray Silverstein) a "pattern language" designed to empower any human being to design and build at any scale. In 1958 he moved to the United States, and has lived in Berkeley, California from 1963 until the present. He is professor emeritus at the University of California, Berkeley. He is now retired and is based in Arundel, Sussex, UK.

http://en.wikipedia.org/wiki/Christopher_Alexander



Keywords“Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice.”




Environment



ProblemEnvironme

nt



ProblemEnvironme

ntSolution



ProblemEnvironme

ntRepetitiv

eSolution



ProblemEnvironme

ntRepetitiv

eSolution Variation

s

Keywords

• Environment

• Problem

• Solution

• Repetitive

• Variations

There are more things in heaven and earth, Horatio,

than are dreamt of in your philosophy.

Hamlet Act 1, scene 5, 159–167

In the Kitchen

Add a mixture of thyme, bay leaf and parsley, tied by the stems or placed in a cloth bag to the soup and remove it before

serving.

In the Kitchen

Add a mixture of thyme, bay leaf and parsley, tied by the stems or placed in a cloth bag to the soup and remove it before

serving. Add a bouquet garni.

At Sea

Tie the rope to hoist or lower the main sail securely to the two-

way turning winch on the left side of the boat when facing

forward.

At Sea

Tie the rope to hoist or lower the main sail securely to the two-

way turning winch on the left side of the boat when facing

forward.Fast the main halyard on the

starboard coffee grinder.

Near a PC

Create a data structure that can

store a list of textual data, allowing me to

iterate through the list from one item to the

next and back.

Near a PC

Create a data structure that can

store a list of textual data, allowing me to

iterate through the list from one item to the

next and back.

Create a double linked list of

strings.

What do Cooking, Sailing and Software Development have in

common ?(besides me loving them)

Communication

Definition“Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice ...”


Addendum

“... and communicate about the problem and solution with others without loosing information and without requiring additional contextual information.”

Christophe Van Ginneken

Keywords

• Environment

• Problem

• Solution

• Repetitive

• Variations

• Communication

T

A G

C A

G

C

T

Why are Design Patterns Important ?

Development Process

Business /Customer

Analysis

Coding

TestingReleaseMgmt

Development Process

Business /Customer

BusinessAnalysis

FunctionalAnalysis

TechnicalAnalysis

Coding

TestingReleaseMgmt

Analysis ProcessBusiness Analysis

Understand Business

Create Process Specifications

Functional Analysis

Design

Create Functional Specifications

Technical Analysis

Choose Technology

Create Technical Specifications

Analysis ProcessBusiness Analysis

Understand Business

Create Process Specifications

Functional Analysis

Design

Create Functional Specifications

Technical Analysis

Choose Technology

Create Technical Specifications

Informal

Formal

Development Process

Business /Customer

Analysis

Coding

TestingReleaseMgmt

Information

Specification

Classic Bug Cost Story

Business /Customer

Analysis Coding Testing


Business /Customer


Informal Formal


Business /Customer


Unpredictable Predictable

Informal Formal

Why are Design Patterns Important ?

How can Design Patterns make a project more

Predictable ?

Business /Customer

Business /Customer

Analysis

Business /Customer

Analysis

Coding

Business /Customer

Analysis

Coding

Testing

Business /Customer

Analysis

Coding

Testing

Business Patterns

FunctionalPatterns

TechnicalPatterns

TestingPatterns

Business /Customer

Analysis

Coding

Testing

Business Patterns

FunctionalPatterns

TechnicalPatterns

TestingPatterns

Design Pattern Tree

Design Pattern Catalog

• List vs Tree

• Selection Criteria

• Grow As You Go

• No Exceptions

• Only Additions

• Quantify

Tree

T

A G

C A

G

C

T

AT TA GC CG

Why are Design Patterns Important for Analysts ?

You

• Give Less

• Get More

• First in Line

• Good Start is Half the Work

• Project Manager’s will love you ;-)

Design Patterns

Summary

• Not only Technical

• Communication

• Formalize Development Process

• Design Pattern Tree

• You can Lead the Way

• Stop Reinventing the Wheel

DNALife’s Design Pattern

Thanks

More...• [email protected]

• feel free to contact me regarding this presentation or modeling in general

• http://themodelfactory.org

• an effort to create a de facto repository of patterns and models, from a modeler’s point of view

• http://thesoftwarefactory.be

• a joint venture of like minded software architects, joining forces to bring UML to the web, enabling a more social modeling experience


http://themodelfactory.org/

http://thesoftwarefactory.org/