2. Chapter one
2
Introduction to software engineering tools and
practices
Contents
•
• Introduction
Basic of CASE tools
3. Definition
3
Software can be defined as a set of programs and
associated documentations.
which includes
A number of separate programs
Configuration files
System documentation
User documentation
4. What is software engineering?
Software engineering is defined as a process of
analyzing user requirements and then designing,
building, and testing software application which will
satisfy those requirements.
IEEE, in its standard 610.12-1990, defines software
engineering as the application of a systematic,
disciplined, which is a computable approach for the
development, operation, and maintenance of
software.
4
5. What is software engineering?
5
Software engineering (SE) is an intellectual activity
and thus human-intensive.
Software is built to meet a certain functional goal and
satisfy certain qualities.
Software processes also must meet certain qualities.
7. Software Engineering Concepts:
Definitions
7
Project: set of activities to develop a software
system.
Activity: a phase in which related tasks
are carried out.
Task: effort that uses resources and produces
work product.
Resources: time, equipment, people (participants)
Work Product: a model, system, or artifact.
10. Software Engineering Tools
10
A software tool is a program that automates some of the labor
involved in the management, design, coding, testing,
inspection, or maintenance of other programs.
Tools allow repetitive, well-defined actions to be automated,
thus reducing the cognitive load on the software engineer.
The engineer is then free to concentrate on the creative aspects
of the process.
Tools are often designed to support particular methods,
reducing any administrative load associated with applying the
method manually.
11. CASE Tools
11
CASE stands for Computer Aided Software Engineering.
It means, development and maintenance of software projects
with help of various automated software tools.
Computer-aided software engineering (CASE) is the
scientific application of a set of tools and methods to a
software system which is meant to result in high-quality,
defect-free, and maintainable software products.
It also refers to methods for the development of
information systems together with automated tools that can
be used in the software development process.
12. CASE Tools…
12
CASE tools are used by software project managers,
analysts and engineers to develop software system.
There are number of CASE tools available to simplify various
stages of Software Development Life Cycle such as Analysis
tools, Design tools, Project management tools, Database
Management tools, Documentation tools are to name a few.
Use of CASE tools accelerates the development of project to
produce desired result and helps to uncover flaws before
moving ahead with next stage in software development.
13. CASE Tools…
13
Therefore, CASE tools include design editors, data
dictionaries, compilers, debuggers, system building tools,
etc.
CASE also refers to the methods dedicated to an
engineering discipline for the development of
information system using automated tools.
CASE is mainly used for the development of quality
software which will perform effectively.
14. CASE Tools…
14
Characteristics of CASE:
It is a graphic oriented tool.
It supports decomposition of process.
Some typical CASE tools are:
Unified Modeling Language
Data modeling tools, and
Source code generation tools.
15. Why CASE Tools?
Architecture management
• Model, design and rapidly build software systems, and
computer applications.
Change and Release Management
• Improve software delivery and life cycle traceability, from
requirements to development.
Software development Management
Align projects for improved productivity and predictability
•
Quality Management
15
•
Ensure software functionality, reliability and
performance
16. Goals of CASE Tools
16
Supply basic functionality, do routine tasks automatically.
Enhance productivity
Increase software quality
Integration with other tools
17. Importance of CASE
17
CASE allows for rapid development of software.
Produce systems with a longer effective operational life.
Produce systems that most closely meet user needs and
requirements.
Produce system with excellent documentation.
Produce systems that needs less systems support.
Produce more flexible systems.
18. Drawbacks of CASE
18
Very complex
Expensive
Difficult to customize
Require training of maintenance staff
Not easily maintainable
Fragile
21. CASE Tools
21
Two types of tools used by software engineers.
1. Analytical tools
Stepwise refinement (top-down design)
Cost-benefit analysis
Software metrics
2. CASE tools
Diagram tools
Process Modeling Tools
Project Management Tools…
22. Symptoms of Software Development Problems
22
Different software development projects fail in different ways.
It is possible to identify a number of common symptoms that
characterize these kinds of projects:
Inaccurate understanding of end-user needs
Inability to deal with changing requirements
Modules that don’t fit together
Software that’s hard to maintain or extend
Late discovery of serious project flaws
Poor software quality
Unacceptable software performance
23. Root Causes of Software Development
Problems
23
Although different projects fail in different ways, it appears that most of
them fail because of a combination of the following root causes:
Ad hoc requirements management
Ambiguous and imprecise communication
Brittle architectures
Overwhelming complexity
Undetected inconsistencies in requirement,
design and implementations
Insufficient testing
Subjective project status assessment
Failure to attack risk
Uncontrolled change propagation
Insufficient automation
24. Software Engineering Best Practices
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what software best practices are all about: commercially
proven approaches to software development that, when used in
combination, strike at the root causes of software development
problems.
These best practices are as follows.
1. Develop software iteratively.
2. Manage requirements.
3. Use component-based architectures.
4. Visually model software.
5. Verify software quality.
6. Control changes to software.
25. Software Engineering Best Practices…
25
1. Develop software iteratively.
This approach is one of continuous discovery, invention, and
implementation, with each iteration forcing the development team to
drive the project’s artifacts to closure in a predictable and repeatable way.
2. Manage requirements.
The challenge of managing the requirements of a software-intensive
system is that they are dynamic: you must expect them to change during
the life of a software project.
Identifying a system’s true requirements—those that weigh most heavily
on the system’s economic and technical goals—is a continuous process.
26. Software Engineering Best Practices…
26
3. Use component-based architectures.
Component-based development (CBD) is an important approach to
software architecture because it enables the reuse or customization of
existing components from thousands of commercially available sources.
4. Visually model software.
Modeling is important because it helps the development team visualize,
specify, construct, and document the structure and behavior of a
system’s architecture.
Using a standard modeling language such as the UML (Unified Modeling
Language), different members of the development team can
unambiguously communicate their decisions to one another.
27. Software Engineering Best Practices…
27
5. Verify software quality.
Software problems are 100 to 1,000 times more expensive to find and
repair after deployment.
For this reason, it’s important to continuously assess the quality of a
system with respect to its functionality, reliability, application
performance, and system performance.
6. Control changes to software.
Coordinating the activities and the artifacts of developers and teams
involves establishing repeatable workflows for managing changes to
software and other development artifacts.