CS 501 Software Engineering Lecture 3 Feasibility Studies 1 CS 501 Spring 2007 Administration Projects Announcements by project groups Email to Course Team Because of spam mail to cs501 l lists cs cornell edu must be sent from the cornell edu domain Or you can send email directly to the Instructor and TAs Their addresses are on the web site But please send email to the entire team 2 CS 501 Spring 2007 Administration Project teams 3 If you do not have a team you can meet after class If you are having difficulty finding a team send email to cs501 l lists cs cornell edu We may ask teams to add extra members If you have definitely chosen a project and reached agreement with your client send email to cs501 l lists cs cornell edu with the names of your team members CS 501 Spring 2007 Feasibility Study A feasibility study is a study made before committing to a project A feasibility study leads to a decision go ahead do not go ahead think again In production projects the feasibility study often leads to a budget request In research a feasibility study is often in the form of a proposal 4 CS 501 Spring 2007 Why are Feasibility Studies Difficult Benefits are usually very hard to quantify e g NSDL Approach is usually ill defined Estimates of resources needed and timetable are very rough e g eCornell Organizational changes may be needed e g Copyright deposit system Therefore feasibility studies rely heavily on the judgment of experienced people Mistakes made at the beginning are the most difficult to correct 5 CS 501 Spring 2007 Why are Feasibility Studies Difficult Advocacy Advocacy is needed to build enthusiasm for a large project to convince an organization to undertake an expensive complex project with many risks Enthusiasm is good but enthusiasts usually emphasize potential benefits and downplay risks People carrying out the feasibility study and making the decision often have a vested interest in the project going ahead e g financial gain career development 6 CS 501 Spring 2007 The Decision Maker s Viewpoint A senior member of an organization must decide whether to begin a major software project What information is needed Client Who is this project for Scope What are the boundaries of the project Benefits What are the benefits Can they be quantified Technical Is the project possible Is there at least one technical way to carry out the project Resources What are the estimates of staff time equipment etc Alternatives What are the options if the project is not begun 7 CS 501 Spring 2007 The Decision Maker s Viewpoint Where are risks Can they be minimized Technical There must be an outline plan with a rough timetable and staff allocation The plan must have a very large margin for contingencies Projects typically require twice the staff and or time envisaged in the feasibility plan External Every system interacts with others Are the others committed to the necessary efforts Where are the external pressures and obstacles 8 CS 501 Spring 2007 Example 1 Benefits of the National Science Digital Library NSDL Concept Create a comprehensive digital library for all aspects of science education where science and education are both defined very broadly The National Science Foundation studied potential benefits for five years before going ahead It came to the conclusion that the potential was sufficient to justify a major program even though the benefits could not be quantified 9 CS 501 Spring 2007 Example 1 NSDL Feasibility Timetable 1996 Vision articulated by NSF s Division of Undergraduate Education 1997 National Research Council workshop 1998 SMETE Lib workshop 1999 NSDL solicitation 2000 6 demonstration projects of the core system 2001 Core integration system funded Five years from concept to decision to definitely go ahead 10 Note Since going ahead the NSF has been less careful about continuing to review the feasibility study after each major iteration CS 501 Spring 2007 Example 2 U S Government Agency Decision before Feasibility Study Outline Description A U S government agency which manages huge numbers of documents and other records has been very slow in moving from a paper based approach to managing digital documents 11 CS 501 Spring 2007 Example 2 Chronology A scientific computing center at University S was commissioned to develop a prototype system to demonstrate technology Funds were approved by Congress to procure a major computer system The National Academy of Sciences was commissioned to report on the technical approach to be followed and the results of the University S prototype feasibility study Note The decision to go ahead was made and the budget approved before the feasibility study was begun 12 CS 501 Spring 2007 Example 2 National Academy Report The National Academy study finds The computer system is technically feasible The University S prototype is promising but incomplete Agency needs stronger technical staff The study was not asked to comment on external factors but discovered major weaknesses in the agency s management structure and organizational skills 13 CS 501 Spring 2007 Example 2 Obvious Problems Organizational Agency senior management clearly not ready to lead a very large project that will completely change the agency No thought given to the workflow and job changes that will affect almost every member of staff Preparation No preliminary study made of volumes or kinds of data nor of the very complex access policies Complexity Major changes in the requirements and design are inevitable once the system goes into production and has real users 14 CS 501 Spring 2007 Example 2 National Academy Report Technical Recommendations The study recommends a phased approach 1 System architecture created by iterative refinement to create a Phase 1 design 2 Followed by sequential implementation using the Phase 1 design Note that this is the same phasing used in the graphics package project discussed in Lecture 2 15 CS 501 Spring 2007 Example 2 Prototype and Phased Development A prototype is not released to users except experimentally In phased development each phase is released into production Developers University prototype Users 16 Demonstration only Build phase 1 Build phase 2 Phase 1 production Phase 2 production Iterative process Sequential process CS 501 Spring 2007 Example 2 Dilemma Agency does not want to return money to Congress National Academy study was paid for by agency and restricted to technical considerations The fundamental problem lies at the senior management
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