Feeds

Sequence diagramming that's fit for purpose

Illustrate your point

Website security in corporate America

Book extract, part 4 In this, the final part of our series of experts from Use Case Driven Object Modeling with UML: Theory and Practice Matt Stephens and Doug Rosenberg show you how to draw lean, purposeful sequence diagrams that are driven from the use cases and preliminary design.

As before, this chapter opens with the following "you are here" diagram of the ICONIX Process, showing in red the area about to be covered.

Iconix Process sequence diagram

Mapping sequence and behavior

All the steps in the process so far have been preparing the use cases for the detailed design activity. By this time, your use case text should be complete, correct, detailed, and explicit. In short, your use cases should be in a state where you can create a detailed design from them.

If you figure that preliminary design is all about object discovery, then detailed design is, by contrast, about behavior allocation - that is, allocating the software functions you've identified into the set of classes you discovered during preliminary design.

When you draw sequence diagrams, you're taking another sweep through the preliminary design, adding in detail. You use sequence diagrams to drive the detailed design. We advocate drawing your sequence diagrams in a minimal style.

Here is our final 10-point checklist for successful sequence diagramming. As with all our lists, pay attention because there will be questions:

Top 10 sequence diagramming guidelines

10. Clean up the static model before proceeding to the next step

9. "Prefactor" your design on sequence diagrams before coding

8. Review your class diagrams frequently while you're assigning operations to classes, to make sure all the operations are on the appropriate classes

7. Assign operations to classes while drawing messages. Most visual modeling tools support this capability

6. Don't spend too much time worrying about focus of control

5. Make sure your use case text maps to the messages being passed on the sequence diagram. Try to line up the text and message arrows.

4. Use the sequence diagram to show how the behavior of the use case is accomplished by the objects

3. Start your sequence diagram from the boundary classes, entity classes, actors, and use case text that result from robustness analysis

2. Do a sequence diagram for every use case, with both basic and alternate courses on the same diagram

1. Understand why you're drawing a sequence diagram, to get the most out of it

Choosing a cloud hosting partner with confidence

More from The Register

next story
'Windows 9' LEAK: Microsoft's playing catchup with Linux
Multiple desktops and live tiles in restored Start button star in new vids
Not appy with your Chromebook? Well now it can run Android apps
Google offers beta of tricky OS-inside-OS tech
New 'Cosmos' browser surfs the net by TXT alone
No data plan? No WiFi? No worries ... except sluggish download speed
SUSE Linux owner Attachmate gobbled by Micro Focus for $2.3bn
Merger will lead to mainframe and COBOL powerhouse
iOS 8 release: WebGL now runs everywhere. Hurrah for 3D graphics!
HTML 5's pretty neat ... when your browser supports it
Greater dev access to iOS 8 will put us AT RISK from HACKERS
Knocking holes in Apple's walled garden could backfire, says securo-chap
NHS grows a NoSQL backbone and rips out its Oracle Spine
Open source? In the government? Ha ha! What, wait ...?
Google extends app refund window to two hours
You now have 120 minutes to finish that game instead of 15
Intel: Hey, enterprises, drop everything and DO HADOOP
Big Data analytics projected to run on more servers than any other app
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.
Security and trust: The backbone of doing business over the internet
Explores the current state of website security and the contributions Symantec is making to help organizations protect critical data and build trust with customers.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.