CS 451 Software Engineering Yuanfang Cai Room 104, University - PowerPoint PPT Presentation

CS 451 Software Engineering Yuanfang Cai Room 104, University Crossings 215.895.0298 yfcai@cs.drexel.edu 1 Drexel University

Are you able to complete your class project on time? 2 Drexel University

Agenda  Risks  Prototype 3 Drexel University

Risk  Most Problems In Software Development Arise Because Of Risk  Things Happen During Development That May Cause Project Failure 4 Drexel University

Risk  Problems That Arise Are Things Like:  Insufficient Computer Time  Inadequate Software Tools  Critical Staff Leave The Project  Wrong Requirements  Incorrect Design  Expected New Equipment (Hardware Or Software) Fails To Arrive  Ambiguous Documents  Projected Schedule Unachievable  Project Cost Estimates Incorrect  Goal - Risk Reduction  Other Engineering Disciplines Use Predictive Models 5 Drexel University

Techniques For Risk Reduction  Prototyping :  Build A Piece Of The Application In The Risk Area  Simulation:  Simulate The Situation  Benchmarking:  Try Out Things That Might Be Bottlenecks 6 Drexel University

Techniques For Risk Reduction  References:  See If Others Have Done It Before  User Questionnaires:  Ask Users About Their Requirements  Analytic Modeling:  Queueing Model, Etc. 7 Drexel University

Prototyping  Very Important Risk Reduction Technique  A Software Prototype:  Actually Executes - It Is A Program  It Has A Lifetime That Depends On Its Purpose(s)  Might Serve Many Purposes  A Key Part Of The Iterative (Spiral) Process 8 Drexel University

Prototyping  Throw-Away Prototype  Build, Use, And Discard  A Throw-Away Prototype Ignores:  Structure, Efficiency, Reliability,  Documentation, Maintainability, Etc.  An Evolutionary Prototype:  Is A Partial Implementation - Implements The Major Risk Areas First  Must Follow Good Engineering Principles - Becomes The Product 9 Drexel University

Multiple Roles Of Prototyping  Requirements Analysis:  Show User Important Parts Of The System  Obtain Users’ Reactions  Requirements Specification:  Prototype Defines System Specifications  Design Feasibility Study:  Evaluate High Risk Design Decisions 10 Drexel University

Multiple Roles Of Prototyping  Human Factors Analysis:  Optimize System Interface  Mouse vs. Keyboard vs. Voice, Etc.  User Training:  Once Specified, Let User Learn About System  Critical Part Of Modern Software Development Method - Risk Reduction 11 Drexel University

Plan a Throw Away Prototype  Plan multiple prototyping using Subversion:  Subversion: http://subversion.apache.org/  An excellent book: “Version Control with Subversion.” The latest copy can be found at http://svnbook.red- bean.com/ though a paper copy can be bought from O’Reilly. 12 Drexel University