Beyond Design: Leveraging UML at Implementation

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Beyond DesignLeveraging UML at Implementation

• Nate Skinner
• Nate.skinner_at_embarcadero.com
• Program Manager
• Application Development Tools
• Embarcadero Technologies, Inc.

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Overview

• Background
• What is Visual Modeling?
• What is UML?
• Why use UML for Analysis and Design?
• Why use UML at Implementation?
• When do I use UML?
• Conclusion

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Background The Problem

• Independent Implementation Efforts
• Different Tools
• Different Delivery Methods
• Things are working as is no need to change
• Introduction of design/models during project
  presents perceived time constraints
• Design phase given different emphasis
• Straight to implementation
• Design seen as best practice, but not practiced
  often
• Slows down development
• Additional step in development process

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Background Its Getting Worse!

• The number of people with expertise to solve
  these problems is dropping!
• Less likely to find architects with real world
  experience
• Have to use tools/technology that allows newer
  users to become productive faster
• More important than ever to deliver artifacts
  about the applications we build

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What is Visual Modeling?

• Software models are very similar to...

Mechanical Drawings
Electrical Schematics
Construction Blueprints
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What is the UML?

• Unified Modeling Language
• An industry standard design notation for
• Expressing software requirements
• Expressing software architecture
• Expressing software dynamics and behavior
• Documenting software deployment
• The de-facto industry standard today
• Current OMG Specification 1.4

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The UML and Software Process

• The UML is a standard notation only
• It does not specify process at all
• UML is most effective when combined with an
  effective software process

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Why use UML for A D?

• Clarity-Graphical depictions of ideas are easier
  to immediately understand

• Audience-This clarity allows a wider audience
  to understand and participate

• Discipline-Modeling, as a rigorous technique,
  imposes discipline on the specifications of
  business problems and a common process to
  understand and resolve them.

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As designed versus As built

• Separate initial design..

Preserve the initial models as a design reference
..from current state
Maintain current models as a working part of your
development environment
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Why use UML for A D?
Clarity-Graphical depictions of ideas are easier
to immediately understand
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Why UML at Implementation?

• Communicating between team members
• Resolving unforeseen problems
• Understanding impact of changes
• Completing error prone steps

• Waiting on finished work from others
• Updating management at code review
• Taking time to document the code

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Benefits of UML at Implementation?

• Task Automation
• Many simple, repetitive tasks can be handled
  automatically
• Visual Guidance
• UML models provide a guide to development and a
  perspective that encourages efficient design
• Communication
• Up to date, design records provide an efficient
  communication vehicle

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Task Automation
Code Generation
public class QuarterHour_ private int
StartTime // Get/Set Methods For Member
Variables public boolean fill( BannerAdList
adList ) boolean returnVal
return returnVal public float
getQHTotal( ) float returnVal
return returnVal public void
computeQHTotal( )

• Saves time and prevents errors by automatically
  creating skeleton for your codea

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Task Automation
EJB Creation

• Create and define all the necessary interfaces to
  build a deployable Java Bean from the UML class

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Task Automation
Adding JavaDoc

• Use a WYSIWYG interface to rapidly enter JavaDoc
  tags for comprehensive documentation

/ The ltBgtSchedule Summary Window lt/Bgtcan
ltIgtdisplay lt/Igta schedule and ltUgtall the
associated datalt/Ugt, including which banner ads
have been assigned to each time slot. /
// not necessary to learn tags or spend time hand
coding JavaDoc
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Visual Guidance
Navigation

• Use picture of code to point and click your way
  through design.

• Navigate between objects on different diagrams
  and within different areas of code visually

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Visual Guidance
Impact Analysis

• View dependencies to determine likely areas of
  impact.

Understand relationships between different
areas within the design
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Visual Guidance
Design Reference

• State diagram and other dynamic diagrams
  (sequence, collaboration, activity, even the
  class) while in the coding phase provide a
  reference to follow while editing/coding.

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Visual Guidance
Design Reference

• View diagrams while coding
• Develop within the same interface
• Or use your choice of IDE

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Visual Guidance
Refactoring

• UML provides the opportunity to visually
  inspect, improve, debug, and enable reuse of code

Refactoring is the process of changing a
software system in such a way that it does not
alter the external behavior of the code yet
improves its internal structure.
Refactoring Improving the Design of Existing
Code Fowler, Martin. 1999. Addison Wesley
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Communication
Team Enabled

• Repository based, managed, scalable, multi user
  access

Web Access Via the Intranet
Local Mode to set-up a repository on local machine
Server Mode for collaboration on a shared
repository
Synchronize
Repository
Synchronize
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Communication
Project Status

• Reports provide quick visual inspection of
  project status

• No special preparation necessary for code review
• Not necessary for management to read thru code or
  accept a verbal status report

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Communication
Learning Curve

• Big picture blueprint of architecture and
  interfaces

• New developers get understanding of overall
  architecture and become more productive more
  quickly.

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When do you use the UML?

• Visual UML modeling has been traditionally
  focused on
• Analysis Design

Implementation
Analysis
Testing
Requirements
Design
yet state of the art tools provide significant
value at Implementation and throughout the
application lifecycle
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Recommended Reading

• The Unified Modeling Language User Guide
• Booch, Grady, J. Rumbaugh, and I. Jacobson.
  1999. Addison Wesley
• Refactoring Improving the Design of Existing
  Code
• Fowler, Martin. 1999. Addison Wesley
• eXtreme Programming eXplained Embrace Change
• Beck, Kent. 2000. Addison Wesley
• Use Case Driven Object Modeling With UML A
  Practical Approach
• Rosenberg, Doug with Kendall Scott. 1999. Addison
  Wesley
• Building Web Applications with UML
• Conallen, Jim. 2000. Addison Wesley
• UML Distilled 2nd Edition
• Fowler, Martin with Kendall Scott. 1997.
  Addison Wesley
• Business Modeling with UML Design Patterns at
  Work
• Eriksson, Hans Erik. And Penker, Magnus. 2000.
  Wiley Computer Publishing