1. Chapter 17 Current Trends in System Development
Systems Analysis and Design in a Changing World, 5th Edition

2. Learning Objectives
Explain the foundations for the adaptive development methodologies
List and describe the features of the Unified Process system development methodology
List and describe the features of Agile Modeling
Compare and contrast the features of Extreme Programming and Scrum development
Explain the importance of Model-Driven Architecture on enterprise-level development
Describe frameworks and components, the process by which they are developed, and their impact on system development

3. Overview The IS discipline is dynamic and always changing
More complex system requirements have necessitated a whole new set of tools
The Unified Process (UP)‏
Radical, adaptive approaches, including Agile Development, Extreme Programming, and Scrum
Model-Driven Architecture for enterprise-level systems
Object frameworks and components to increase productivity and quality

4. Software Principles and Practices
Ubiquitous computing is the current trend in our society
Using computer technology in every aspect of our lives
The effort to develop current solutions is demanding
Current trends in modeling and development processes use five important principles
Abstraction
Process of extracting core principles from a set of facts or statement
Example: Metamodels describe the characteristics of another model
Models and modeling
An abstraction of something in the real world, representing a particular set of properties

5. Software Principles and Practices (cont’d)‏
Patterns
Standard solutions to a given problem or templates that can be applied to a problem
Reuse
Building standard solutions and components that can be used over and over again
Methodologies
A process—including the rules, guidelines, and techniques—that defines how systems are built

6. Adaptive Approaches to Development
Opposite end of spectrum from predictive approaches (recall Chapter 2)‏
Allow for uncertainty
Use empirical controls, not predictive controls
Describe processes that are variable and unpredictable
Monitor progress and make corrections on the fly

7. Adaptive Approaches to Development— Characteristics
Less emphasis on up-front analysis, design, and documentation
More focus on incremental development
More user involvement in project teams
Reduced detailed planning
Used for near-term work phases only
Tightly control schedules by fitting work into discrete time boxes
More use of small work teams that are self-organizing

8. The Unified Process (UP)‏
Object-oriented system development methodology (system development process)‏
Offered by Rational/IBM, UP developed by Booch, Rumbaugh, and Jacobson
UP should be tailored to organizational and project needs
Highly iterative life cycle
Project will be use-case driven and modeled using UML

9. The Unified Process Life Cycle
UP life cycle
Includes four phases which consist of iterations
Iterations are “mini-projects”
Inception – develop and refine system vision
Elaboration – define requirements and design and implement core architecture
Construction – continue design and implementation of routine, less risky parts
Transition – move the system into operational mode

10. The Unified Process Life Cycle
Figure 17-1

11. UP Phases and Objectives
Figure 17-2

12. The UP Disciplines UP defines disciplines used within each phase
Discipline – set of functionally related development activities
Each iteration includes activities from all disciplines
Activities in each discipline produce artifacts – models, documents, source code, and executables
Learning CIS/MIS means learning techniques from these disciplines
Six main UP development disciplines
Business modeling, requirements, design, implementation, testing, and deployment
Three additional support disciplines
Project management, configuration and change management, and environment

13. The UP Disciplines (cont’d)‏
Six main UP development disciplines
Business modeling, requirements, design, implementation, testing, and deployment
Three additional support disciplines
Project management, configuration and change management, and environment

14. UP Disciplines Used in Varying Amounts in Each Iteration
Figure 17-3

15. UP Life Cycle Model Showing Phases, Iterations, and Disciplines
Figure 17-4

16. The Agile Development Philosophy and Modeling
Agile Development Principles
A philosophy and set of guidelines for developing software in an unknown, rapidly changing environment
Requires agility – being able to change direction rapidly, even in the middle of a project
Agile Modeling Principles
A philosophy about how to build models, some of which are formal and detailed and others are sketchy and minimal

17. Adaptive Methodologies Using Agile Modeling
Figure 17-5

18. The Agile Development Philosophy and Values
Responding to change over following a plan
An agile project is chaordic – both chaotic and ordered
Individuals and interactions over processes and tools
Working software over comprehensive documentation
Customer collaboration over contract negotiation

19. Agile Modeling Principles
AM is about doing the right kind of modeling at the right level of detail for the right purposes
Use models as a means to an end instead of building models as end deliverables
Does not dictate which models to build or how formal to make those models
Has basic principles to express the attitude that developers should have as they develop software

20. Agile Modeling Principles
Figure 17-6

21. Agile Modeling Practices
Figure 17-7

22. Extreme Programming (XP)‏
An adaptive, agile development methodology created in the mid-1990s
Takes proven industry best practices and focuses on them intensely
Combines those best practices (in their intense form) in a new way to produce a result that is greater than the sum of the parts

23. XP Core Values Communication Simplicity Feedback Courage
In open, frequent verbal discussions
Simplicity
In designing and implementing solutions
Feedback
On functionality, requirements, designs, and code
Courage
In facing choices such as throwing away bad code or standing up to a too-tight schedule

24. Some XP Practices Planning Testing Pair programming Simple designs
Users develop a set of stories to describe what the system needs to do
Testing
Tests are written before solutions are implemented
Pair programming
Two programmers work together on designing, coding, and testing
Simple designs
“KISS” and design continuously

25. Some XP Practices (cont’d)‏
Refactoring
Improving code without changing what it does
Owning the code collectively
Anyone can modify any piece of code
Continuous integration
Small pieces of code are integrated into the system daily or more often
System metaphor
Guides members towards a vision of the system

26. Some XP Practices (cont’d)‏
On-site customer
Intensive user/customer interaction required
Small releases
Produce small and frequent releases to user/customer
Forty-hour work week
Project should be managed to avoid burnout
Coding standards
Follow coding standards to ensure flexibility

27. XP Core Values and Practices
Figure 17-8

28. XP Project Activities System-level activities Release-level activities
Occur once during each development project
Involve creating user stories to planning releases
Release-level activities
Cycle multiple times – once for each release
Are developed and tested in a period of no more than a few weeks or months
Iteration-level activities
Code and test a specific functional subset in a few days or weeks

29. XP Development Approach
Figure 17-9

30. Scrum A quick, adaptive, and self-organizing development methodology
Named after rugby’s system for getting an out-of-play ball into play
Responds to a current situation as rapidly and positively as possible
A truly empirical process control approach to developing software

31. Scrum Philosophy Responsive to a highly changing, dynamic environment
Focuses primarily on the team level
Team exerts total control over its own organization and work processes
Uses a product backlog as the basic control mechanism
Prioritized list of user requirements used to choose work to be done during a Scrum project

32. Scrum Organization Product owner Scrum master Scrum team or teams
The client stakeholder for whom a system is being built
Maintains the product backlog list
Scrum master
Person in charge of a Scrum project
Scrum team or teams
Small group of developers
Set their own goals and distribute work among themselves

33. Scrum Practices Sprint Parts of a sprint
The basic work process in Scrum
A time-controlled mini-project
Firm 30-day time box with a specific goal or deliverable
Parts of a sprint
Begins with a one-day planning session
A short daily Scrum meeting to report progress
Ends with a final half-day review

34. Scrum Software Development Process
Figure 17-10

35. Project Management and Adaptive Methodologies
Project time management
Smaller scope and focused on each iteration
Realistic work schedules
Project scope management
Users and clients are responsible for the scope
Scope control consists of controlling the number of iterations
Project cost management
More difficult to predict because of unknowns
Project communication management
Critical because of open verbal communication and collaborative work

36. Project Management and Adaptive Methodologies (cont’d)‏
Project quality management
Continual testing and refactoring must be scheduled
Project risk management
High-risk aspects addressed in early iterations
Project human resource management
Teams organize themselves
Project procurement management
Integrating purchased elements into the overall project
Verifying quality of components
Satisfying contractual commitments

37. Model-Driven Architecture
Model-Driven Architecture (MDA) is an OMG (Object Management Group) initiative
Built on the principles of abstraction, modeling, reuse, and patterns
Provides companies with a framework to identify and classify all system development work being done in an enterprise
MDA extracts current systems features and information and combines them into a platform independent model (PIM)‏

38. Model-Driven Architecture (cont’d)‏
Platform-independent model (PIM)‏
Describes system characteristics that are not specific to any deployment diagram
Uses UML
Platform-specific model (PSM)‏
Describes system characteristics that include deployment platform requirements
A set of standard transformations by the OMG move a PSM to a PIM

39. Software Development and MDA
Figure 17-11

40. Metamodels and Transitions between PIM, PSM, and Code
Figure 17-12

41. Partial Metamodel of UML Class Diagram
Figure 17-13

42. Object Frameworks
A set of classes that are designed to be reused in a variety of programs
The classes within an object framework are called foundation classes
Can be organized into one or more inheritance hierarchies
Application-specific classes can be derived from existing foundation classes

43. Object Framework Types
User-interface classes
Commonly used objects within a GUI
Generic data structure classes
Linked lists, binary trees, and so on, and related processing operations
Relational database interface classes
Classes to create and perform operations on tables
Classes specific to an application area
For use in a specific industry or application type

44. Impact on Design and Implementation
Frameworks must be chosen early in the project
Systems design must conform to specific assumptions about application program structure and operation that the framework imposes
Design and development personnel must be trained to use a framework effectively
Multiple frameworks might be required, necessitating early compatibility and integration testing

45. Components Software modules that are fully assembled and ready to use
Reusable packages of executable code
Have well-defined interfaces to connect them to clients or other components
Public interfaces and encapsulated implementation
Standardized and interchangeable
Updating a single component does not require relinking, recompiling, and redistributing an entire application

46. Component Standards and Infrastructure
Interoperability of components requires standards to be developed and readily available
Components might also require standard support infrastructure
Software components have more flexibility when they can rely on standard infrastructure services to find other components
Networking standards are required for components in different locations

47. CORBA and COM+
CORBA (Common Object Request Broker Architecture) is a standard for software component connection and interaction developed by the OMG
An object request broker (ORB) provides component directory and communication services
The Internet Inter-ORB Protocol (IIOP) is used to communicate among objects and ORBs
Component Object Model Plus (COM+) is a standard for software component connection and interaction developed by Microsoft

48. Enterprise JavaBeans
Part of the Java programming language’s extensive object framework (JDK)‏
A JavaBean can execute on a server and communicate with clients and other components using CORBA
A JavaBean implements the required component methods and follows the required naming conventions of the JavaBean standard
Platform independent

49. Components and the Development Life Cycle
Component purchase and reuse is a viable approach to speeding completion of a system
Purchased components can form all or part of a newly developed or re-implemented system
Components can be designed in-house and deployed in a newly developed or re-implemented system

50. Using Purchased Components— Implications
Standards and support software of purchased components must become part of the technical requirements definition
A component’s technical support requirements restrict the options considered during software architectural design

51. Monitoring System Performance
Examine component-based designs to estimate network traffic patterns and demands on computer hardware
Examine existing server capacity and network infrastructure to determine their ability to accommodate communication among components
Upgrade network and server capacity prior to development and testing
Test system performance during development and make any necessary adjustments
Continuously monitor system performance after deployment to detect emerging problems
Redeploy components, upgrade server capacity, and upgrade network capacity to reflect changing conditions

52. Services
New method of software reuse enabled by Internet— external services identified and used for applications
Called Web services and service-oriented architecture (SOA)‏
Microsoft .NET is service standard based on SOAP
Java 2 Web Services (J2WS) is service standard for services in Java

53. Component Communication Using SOAP
Figure 17-14

54. Summary Adaptive development methodologies Unified Process (UP)‏
Agile Modeling and Agile Development
Flexibility in an unpredictable business world
Extreme Programming (XP)‏
Tests are written first; programmers work in pairs
Scrum
Defines a specific goal that can be completed within four weeks