 The Rise of Computer Science ◦ Machine Language (1 st Gen) ◦ Assembly Language (2 nd Gen) ◦ Third Generation Languages (FORTRAN, BASIC, Java, C++, etc.) ◦ CASE (4 th Gen)?  IT System Complexity

The CHAOS Report (1994)  Produced by the Standish Group via surveys, focus groups, and case studies  4_1.php 4_1.php  Project Resolution Types ◦ Success = On-Time, On-Budget, Fully Featured ◦ Challenged = Over-Time, Over-Budget, Fewer Features ◦ Impaired = Cancelled  A lot of interesting findings about Software Development track record

The CHAOS Report (1994) Findings

Project Success Factors “The three major reasons that a project will succeed are user involvement, executive management support, and a clear statement of requirements. There are other success criteria, but with these three elements in place, the chances of success are much greater. Without them, chance of failure increases dramatically.” – The Chaos Report (1994), Standish Group Project Success Factors % of Response s 1. User Involvement 15.9% 2. Executive Management Support 13.9% 3. Clear Statement of Requirements 13.0% 4. Proper Planning 9.6% 5. Realistic Expectations 8.2% 6. Smaller Project Milestones 7.7% 7. Competent Staff 7.2% 8. Ownership 5.3% 9. Clear Vision & Objectives 2.9% 10. Hard-Working, Focused Staff 2.4% Other13.9%

 p.3: "Systems analysis and design emerged from the need to perform certain activities around, and particularly prior to, the steps involved in developing a computer system using software engineering tools and techniques."

Specification Planning Programming Operation Cost of Defects

 A process: a series of steps involving activities, constrains, and resources that produce an intended ouput of some kind  A process involves a set of tools and techniques

 Phase I Requirements ◦ All balls must remain in motion ◦ Only one person at a time can touch a ball (ball must be passed in the air) ◦ Each person may only touch one ball at a time ◦ Juggle for 15 seconds without dropping the ball  Phase II Requirements ◦ All phase I requirements apply ◦ The ball cannot be passed to the person by your side

 Impose consistency and structure on a set of activities  Guide us to understand, control, examine, and improve the activities  Enable us to capture our experiences and pass them along

Carnegie Mellon University

 Waterfall model  V model  Prototyping model  Operational specification  Transformational model  Spiral model  Phased development: increments and iterations  Agile methods

 One of the first process development models proposed  Works for well understood problems with minimal or no changes in the requirements  Simple and easy to explain to customers  It presents a very high-level view of the development process sequence of process activities  Each major phase is marked by milestones and deliverables (artifacts)

This version differs from the book but the idea is the same:

 There is no iteration in waterfall model  Most software developers apply a great many iterations

 Provides no guidance on how to handle changes to requirements/design during development (assumes requirements/design can be frozen)  Views software development as manufacturing process rather than as creative process  There is no iterative activities that lead to creating a final product  Long wait before a final product  Lacks Business Process Redesign!

 Shorter cycle time  System delivered in pieces ◦ enables customers to have some functionality while the rest is being developed  Allows two systems functioning in parallel ◦ the production system (release n): currently being used ◦ the development system (release n+1): the next version

 Incremental development: starts with small functional subsystem and adds functionality with each new release  Iterative development: starts with full system, then changes functionality of each subsystem with each new release

 Phased development is desirable for several reasons ◦ Training can begin early, even though some functions are missing ◦ Markets can be created early for functionality that has never before been offered ◦ Frequent releases allow developers to fix unanticipated problems globaly and quickly ◦ The development team can focus on different areas of expertise with different releases

 Emphasis on flexibility in producing software quickly and capably  Agile manifesto Value individuals and interactions over process and tools Prefer to invest time in producing working software rather than in producing comprehensive documentation Focus on customer collaboration rather than contract negotiation Concentrate on responding to change rather than on creating a plan and then following it

 Extreme programming (XP)  Crystal: a collection of approaches based on the notion that every project needs a unique set of policies and conventions  Scrum: 30-day iterations; multiple self- organizing teams; daily “scrum” coordination

 What about process redesign? ◦ What does it profit the business if all we do is automate the process as is? ◦ What about COTS? ◦ What is the answer?