Use Cases Promises A Lot!

No More Misunderstandings!

Client Commitment!

Filled With Information

In Theory…

Complete

In practice…

Give no details

Give no sequence

Give only parts of the requirements

”Use case diagrams are very close to useless ” - Martin Fowler

Use lots of words that can be

misunderstood

Use Cases Alone Aren't the

Answer to Everything

This Is My List Of Models To

Supplement A Use Case

The Meaning of Words

Abstract Concepts

Signs (Words, Icons, Sounds)

”Tri:”

Real World Objects

The Semiotic Triangle

Words refer to abstract concepts in our minds that

refer to the ”real world objects” we experience

What you consider a fast vehicle depends on your

previous experiences and your context

The Glossary

The Glossary defines terms used so that we all

get the same ”picture”

Example of Glossary

Class diagram and entity models can be used to

define terms in a glossary

Is it?

Or?

Uses Customer Product

Pays for Customer Product

2. Navigating the Use Case

A Use Case with lots of Alternatives and

Exceptions may turn into a Labyrinth!

The flow chart

A flow chart creates an overview

and makes a use case easier to navigate

Example of Flow Chart

The Use Case Sequence

A Use Case Diagram does

not tell you in which order

you do things

Bake Pizza

Sell Pizza

Settle payment

The Business Process Do…

The Business Process Model helps putting the

use cases in perspective and in sequence

They facilitate understanding the businesses

priorities

3. The Business Process Model

3. The Business Process Model

Who

When

Use Case 2 Use Case 1

4. Role to Actor Map

Everybody wants to be Arnold!

4. Role to Actor Map

Not everyody is…

4. Role to Actor Map

Actors are not organizational roles!

They are entities that interact with

the system

4. Role to Actor Map

One Organizational Role can translate to many

Actors…

One Actor can translate to many

Organizational Roles…

4. Role to Actor Map

<<Organizational Role>>

CEO

<<Organizational Role>>

CEO Secretary

<<Organizational Role>>

Marketing Analyst

<<trace>>

<<trace>>

<<trace>>

Which Is Our Goal?

Which Is Our Goal?

The Goal Model helps making sure that everyone

is working in the same direction and is used to

prioritize and discard requirements

5. The Goal Model

Class diagram and entity models can be used to

create a goal model

Leads to <<Goal>>

Low Costs <<Goal>>

Large Profit

Leads to <<Problem>>

Sad Customers <<Goal>>

High Prices

Leads to

Part of the Picture

A use Case only gives

part of the picture

Create and assign issue

Close Issue

Schedule issue

Estimate issue

Resolve issue

Verify solution

Put issue on hold

A More Complete Picture

Created

Assigned

Estimated Scheduled Resolved

On Hold

Verified

Closed

6. The State Chart

A State Chart shows the life cycle of one object

cross cutting several use cases, giving you a

more comprehensive view

Structural Business Rules

Constraints we put on the information we store

Structural Business Rules

Class diagram and entity models can be used to

define structural business rules

Can we register people who has not yet bought

anything?

0..* Customer Product

Has bought

1..* Customer Product

Has bought

8. Generic requirements

Requirements that affect more than one use

case, often quality attributes

8. The system generic requirements

<<Performance Requirement>>

95% of pages must respond in 8 seconds or less

(Sub)system

Business Rules

If

Sweden wins against Norway at the same time

that Denmark looses against Canada and

Norway wins against Russia

or

if Sweden wins against Norway and Denmark

then

Sweden will become world champions in ice

hockey!

9. The Business Rules

Sweden is world champion

Or

And

Sweden beat Norway

And

Canada beat Denmark

Norway beat Russia

if

then

if if

Sweden beats Denmark

if

If

Sweden wins against Norway at the same time that

Denmark looses against Canada and Norway wins

against Russia

or

if Sweden wins against Norway and Denmark

then Sweden will become world champions in ice

hockey!

Where do we find the function?

Navigation Map

Start

Buy Admin Analyze Register

Search Product

Place Order

Cancel Pay

10. Navigation Map

The Navigation Map shows how the user can

navigate between functions

Modeling Languages

1. Glossary – UML Class Diagram

2. Flow Chart – UML Activity Diagram

3. Business Process Model – BPMN Diagram*

4. Role Actor Map – UML Class Diagram

5. Goal Model – UML Class Diagram

6. Life Cycle – UML State Diagram

7. Structural Business Rules – UML Class Diagram

8. Generic Requirements – SysML Requirements Diagram**

9. Business Rules – UML Composite Structure Diagram

10. Navigation Map – UML Class Diagram

* Can also use UML Activity Diagram ** Can also use UML Class Diagram

Where are we now?

Where are we now?

Complete

Wedding rings; Jeff Belmonte from Cuiabá, Brazil (http://commons.wikimedia.org/wiki/File:Wedding_rings.jpg)

Boxing gloves; Karnaz (http://commons.wikimedia.org/wiki/File:Osaka_Fight_Gear_Muay_Thai_Gloves.jpg)

42; by Patrick Hoesly (http://www.flickr.com/photos/zooboing/3283020161/sizes/o/in/photostream/)

Sarah Palin Debate Flow Chart (http://adennak.com/blog/wordpress/2008/10/moosehunter/)

Pizza process by Tharanga Jalathge (http://creately.com/diagram/example/h5ulaq521/Pizza+Delivery+Process)

Goals by Jurgen Appelo (http://www.flickr.com/photos/jurgenappelo/5201843170/sizes/o/in/photostream/)

Image Credits

10 models to supplement

your use cases

By Andreas Hägglund

http://www.linkedin.com/in/andreashagglund

Corporate website: http://www.systemvaruhuset.se/

Personal website: http://www.systemvaruhuset.net/

10 models to supplement your use cases © Andreas Hägglund, Systemvaruhuset June 10, 2013