1. Software Engineering and Best Practices
Sources: Various.
Rational Software Corporation slides,
OOSE textbook slides, Per Kroll talk, How to Fail with the RUP article, textbooks
Most slides have been modified considerably

2. What is software engineering ??
Software Engineering is an engineering discipline which is concerned with all aspect of software production from the early stages of system specification through to maintaining the system after it has gone into use.

3. What is software engineering ??
Software Engineers must adopt a systematic and organized approach to their work and use appropriate tools and techniques depending on the problem to be solved , development constraints, and the resource availability”

4. What is a software process ??
IEEE - A process is a sequence of steps performed for a given purpose
A set of activities whose goal is the development or evolution of software
General activities in all software processes :
Specification: what the system should do and it’s development constrains
Development: production of the software
Validation: checking that the software is what the customer wants
Evolution : changing the software in response to changing demands

5. Comments: $250 billion annually in US. Over 175,000 projects!
Complexity, size, distribution, importance push our limits.
Business pushes these limits:
Great demands for rapid development and deployment
 Incredible pressure: develop systems that are:
On time,
Within budget,
Meets the users’ requirements
Figures in the late 90s indicated that at most
70% of projects completed
Over 50% ran over twice the intended budget
$81 billion dollars spent in cancelled projects!!
Getting better, but we need better tools and techniques!

6. What Happens in Practice
Sequential activities: (Traditional ‘Waterfall’ Process)
Requirements Design Code Integration Test
Late Design Breakage
Integration Begins
100%
Risk inadequately addressed
Process not receptive to Change
Problems not really ‘seen’
until near delivery date!
Until then, ‘all is well…’
Big Bang approach – full delivery
Long development cycles…
Little user involvement, etc. etc…
Development Progress (% coded)
Original
Target Date
Project Schedule

7. The Result is Often Referred to as the Software Crisis
Schedule Overruns
Cost Estimate Overruns
Software Quality Problems
Software does not meet User Expectations
Productivity of Software Developers has not been keeping up with demand
Especially since the rise of the Internet
until the internet bubble exploded in the Spring of 2000

8. Why is This? Software is Dynamic versus Static Software is Complex
Software is difficult to Conceptualize
Software is difficult to Represent
Software is difficult to Communicate
Software is difficult to Evaluate and Measure
Software Developers have trouble learning what users want:
Users do not know what they want
Software developers misunderstand the problem
There is a tremendous demand for software

9. What can we do about it? The Triangle For Success The needed elements for a successful project
You need all three facets—a notation, a process, and a tool.
You can learn a notation, but if you don't know how to use it (process), you will probably fail.
You may have a great process, but if you can't communicate the process (notation), you will probably fail.
And lastly, if you cannot document the artifacts of your work (tool), you will probably fail.

10. The Role of Process We need a process that
Will serve as a framework for large scale and small projects
 Adaptive – embraces ‘change!’
Opportunity for improvement not identification of failure!
Iterative (small, incremental ‘deliverables’)
Risk-driven (identify / resolve risks up front)
Flexible, customizable process (not a burden; adaptive to projects)
Architecture-centric (breaks components into ‘layers’ or common areas of responsibility…)
Heavy user involvement
Captures and institutionalizes best practices of Software Engineering
Identify best ways of doing things

11. The Role of Notation
Notation plays an important part in any model—it is the glue that holds the process together. ? Notation has three roles:
It serves as the language for communicating decisions that are not obvious or can be inferred from the code itself.
It provides semantics that are rich enough to capture all important strategic and tactical decisions.
It offers a form concrete enough for humans to reason and for tools to manipulate?

12. The Role of Tool
Any software development method is best supported by a tool
The Rational Rose product family is designed to provide the software developer with a complete set of visual modeling tools for development of robust, efficient solutions to real business needs in the client/server, distributed enterprise, and real-time systems environments.
Rational Rose products share a common universal standard, making modeling accessible to nonprogrammers wanting to model business processes as well as to programmers modeling applications logic.

13. What is CASE Tool Computer Aided Software Engineering
Software systems which are intended to provide automated support for software process activities
CASE tools are:
Upper-CASE : tools to support early process activities of requirement and design
Lower-CASE : tools to support later activities such as programming, debugging and testing

14. Why Rational Software??
Rational software covers the entire lifecycle of software production.
Rational software provides methodology (process) and tools to cover all aspects of software production.