The Common Process Framework for OO
20.4.1 The Common Process Framework for OO
A common process framework defines an organization’s approach to software engi- neering. It identifies the paradigm that is applied to build and maintain software and the tasks, milestones, and deliverables that will be required. It establishes the degree of rigor with which different kinds of projects will be approached. The CPF is always adaptable so it can meet the individual needs of a project team. This is its single most important characteristic.
As we noted earlier in this chapter, object-oriented software engineering applies The common process
XRef
a process model that encourages iterative development. That is, OO software evolves framework defines basic software
through a number of cycles. The common process framework that is used to man- engineering activities.
age an OO project must be evolutionary in nature. It is described in
Ed Berard [BER93] and Grady Booch [BOO91] among others suggest the use of a Chapter 2.
“recursive/parallel model” for object-oriented software development. In essence the recursive/parallel model works in the following way:
• Do enough analysis to isolate major problem classes and connections. • Do a little design to determine whether the classes and connections can
be implemented in a practical way.
CHAPTER 20
OBJECT-ORIENTED CONCEPTS AND PRINCIPLES
• ? Extract reusable objects from a library to build a rough prototype.
How do we
apply a
• Conduct some tests to uncover errors in the prototype.
recursive/parallel model for OO
• Get customer feedback on the prototype.
software
• Modify the analysis model based on what you’ve learned from the prototype,
engineering?
from doing design, and from customer feedback. • Refine the design to accommodate your changes. • Code special objects (that are not available from the library). • Assemble a new prototype using objects from the library and the new objects
you’ve created. • Conduct some tests to uncover errors in the prototype. • Get customer feedback on the prototype.
This approach continues until the prototype evolves into a production application. The recursive/parallel model is quite similar to the spiral or evolutionary para- digm. Progress occurs iteratively. What makes the recursive/parallel model different is (1) the recognition that analysis and design modeling for OO systems cannot be accomplished at an even level of abstraction and (2) analysis and design can be applied to independent system components concurrently. Berard [BER93] describes the model in the following manner:
• Systematically decompose the problem into highly independent components. • Reapply the decomposition process to each of the independent components
to decompose each further (the recursive part). • Conduct this reapplication of decomposition concurrently on all components
(the parallel part). • Continue this process until completion criteria are attained.
It’s important to note that this decomposition process is discontinued if the ana- lyst/designer recognizes that the component or subcomponent required is available in a reuse library.
To control the recursive/parallel process framework, the project manager must In many ways, the
recognize that progress is planned and measured incrementally. That is, project tasks architecture of an OO
and the project schedule are tied to each of the “highly independent components,” system makes it easier
to initiate work in
and progress is measured for each of these components individually.
parallel. However, be Each iteration of the recursive/parallel process requires planning, engineering certain that each
(analysis, design, class extraction, prototyping, and testing), and evaluation activi- parallel task is defined
ties (Figure 20.11). During planning, activities associated with each of the indepen- so that progress can
be assessed. dent program components are planned and scheduled. (Note: With each iteration, the schedule is adjusted to accommodate changes associated with the preceding iter- ation.) During early stages of engineering, analysis and design occur iteratively. The
Planning Analysis Design
Review and refinement
Early analysis/design iterations
Analysis Design
Analysis
Design
Review and refinement
Extract
Planning Analysis
Customer First
classes
evaluation prototype
Review and refinement
Extract
Planning Analysis
Customer Next
classes
evaluation increment
Review and refinement
Customer nth
reusable
classes
evaluation increment
F I G U R E 20.11 Typical process sequence for an OO project
intent is to isolate all important elements of the OO analysis and design models. As engineering work proceeds, incremental versions of the software are produced. Dur- ing evaluation, reviews, customer evaluation, and testing are performed for each increment, with feedback affecting the next planning activity and subsequent incre- ment.
Parts
» The Concurrent Development Model
» SUMMARY Software engineering is a discipline that integrates process, methods, and tools for
» PEOPLE In a study published by the IEEE [CUR88], the engineering vice presidents of three
» THE PROCESS The generic phases that characterize the software process—definition, development,
» THE PROJECT In order to manage a successful software project, we must understand what can go
» METRICS IN THE PROCESS AND PROJECT DOMAINS
» Extended Function Point Metrics
» METRICS FOR SOFTWARE QUALITY
» INTEGRATING METRICS WITHIN THE SOFTWARE PROCESS
» METRICS FOR SMALL ORGANIZATIONS
» ESTABLISHING A SOFTWARE METRICS PROGRAM
» Obtaining Information Necessary for Scope
» An Example of LOC-Based Estimation
» QUALITY CONCEPTS 1 It has been said that no two snowflakes are alike. Certainly when we watch snow
» SUMMARY Software quality assurance is an umbrella activity that is applied at each step in the
» R diagram 1.4 <part-of> data model; data model <part-of> design specification;
» SYSTEM MODELING Every computer-based system can be modeled as an information transform using an
» Facilitated Application Specification Techniques
» Data Objects, Attributes, and Relationships
» Entity/Relationship Diagrams
» Hatley and Pirbhai Extensions
» Creating an Entity/Relationship Diagram
» SUMMARY Design is the technical kernel of software engineering. During design, progressive
» Data Modeling, Data Structures, Databases, and the Data Warehouse
» Data Design at the Component Level
» A Brief Taxonomy of Styles and Patterns
» Quantitative Guidance for Architectural Design
» Isolate the transform center by specifying incoming and outgoing
» SUMMARY Software architecture provides a holistic view of the system to be built. It depicts the
» The User Interface Design Process
» Defining Interface Objects and Actions
» D E S I G N E VA L U AT I O N
» Testing for Real-Time Systems
» Organizing for Software Testing
» Criteria for Completion of Testing
» The Transition to a Quantitative View
» The Attributes of Effective Software Metrics
» Architectural Design Metrics
» Component-Level Design Metrics
» SUMMARY Software metrics provide a quantitative way to assess the quality of internal product
» Encapsulation, Inheritance, and Polymorphism
» Identifying Classes and Objects
» The Common Process Framework for OO
» OO Project Metrics and Estimation
» Event Identification with Use-Cases
» SUMMARY Object-oriented analysis methods enable a software engineer to model a problem by
» Partitioning the Analysis Model
» Designing Algorithms and Data Structures
» Program Components and Interfaces
» SUMMARY Object-oriented design translates the OOA model of the real world into an
» Testing Surface Structure and Deep Structure
» Deficiencies of Less Formal Approaches 1
» What Makes Cleanroom Different?
» Design Refinement and Verification
» SUMMARY Cleanroom software engineering is a formal approach to software development that
» Structural Modeling and Structure Points
» Describing Reusable Components
» SUMMARY Component-based software engineering offers inherent benefits in software quality,
» Guidelines for Distributing Application Subsystems
» Middleware and Object Request Broker Architectures
» An Overview of a Design Approach
» Consider expert Web developer will create a complete design, but time and cost can be appropriate
» A Software Reengineering Process Model
» Reverse Engineering to Understand Data
» Forward Engineering for Client/Server Architectures
» SUMMARY Reengineering occurs at two different levels of abstraction. At the business level,
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