Chapter 1 The Role of the Systems Analyst

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1 systems Major Topics Professor Merrill Warkentin Mississippi State University information systems (categories) systems analysis and design phases of analysis and design (SDLC) CASE tools 2 Information Definition organizational resource must be managed costs associated with processing a set of interrelated, interacting components that function together as an entity to achieve specific results regularly interacting or interdependent group of items forming a unified whole (Webster) General s Theory closed vs. open, feedback loops, self-regulating 3 4 Open and Closed s s 5 open free-flowing information output from one system becomes input to another closed with restricted access to information limited by numerous rules information on a need to know basis can be treated as a black box (inside = mystery) 6 boundary Sub- boundary spanners Physical s tree, colony of ants solar system equilibrium Environment of economic, legal, competitive regulatory, political, cultural transient components (in transformation out) Social s team, club, church, school company, corporation, agency nation global economic system Copyright 2005, Merrill Warkentin page 1

2 Management Information s Information s 7 a subsystem of the organization comprised of subsystems - DBMS, O-E-P system, billing, etc. Environment = Organization MIS DBMS provide reports Other Depts Financial 8 transaction processing systems (TPS) office automation systems (OAS) knowledge work systems (KWS) management information systems (MIS) decision support systems (DSS) executive support systems (ESS) group decision support systems (GDSS) expert systems (ES) New Technologies Technology Impact on ecommerce & the Web Enterprise Resource Planning (ERP) integration of different information systems within the corporation wireless and handheld devices mobile commerce (m-commerce) open source software individual personal productivity software team / workgroup groupware, collaboration software organization knowledge management, ERP society communities, privacy, education 9 10 s Analysis and Design s Analysts systematic approach to identifying problems opportunities objectives analyzing the information flows designing computerized information systems to solve problems act as outside consultants to businesses supporting experts within a business change agents are problem solvers require communication skills must be ethical with users and customers Copyright 2005, Merrill Warkentin page 2

3 s Development Life Cycle Phase 1: Identifying Problems a systematic approach to solving problems divided into seven phases each phase has unique activities 7 Implementing and evaluating the system 1 Identifying problems, opportunities, and objectives 2 Determining information requirements 3 Analyzing system needs 4 Designing the recommended system identifying need for a new or an improved information system problems opportunities objectives personnel involved analyst user management systems management 13 6 Testing and maintaining the system 5 Developing and documenting software 14 Phase 2: Determining Information Requirements Phase 3: Analyzing Needs 15 interview management, operations personnel gather systems/operating documents use questionnaires observe the system and personnel involved learn the who, what, where, when, and how, and the why for each of these 16 evaluate current system & procedures create data flow diagrams (DFD) document procedural logic for data flow diagram processes complete the data dictionary model semi-structured decisions prepare and present the system proposal recommend the optimal solution to management Phase 4: Designing Phase 5: Developing & Documenting Software 17 design user interface (input/output) design system controls design files and/or database produce program specifications produce decision trees or tables Top-Down Design logical business aspects, data flow physical hardware, OS, language 18 design computer programs using structure charts and pseudocode walkthrough program design write computer programs document software with help files, procedure manuals, and Web sites with frequently asked questions Copyright 2005, Merrill Warkentin page 3

4 Phase 6: Testing & Maintaining Phase 7: Implementing & Evaluating 19 test and debug computer programs test the computer system remove undetected errors enhance system adding features 20 plan conversion train users purchase and install new equipment convert files install system review and evaluate system maintain system over time update, fix, improve, etc. Enhancements Resource Consumption adding additional features to the system business and governmental requirements change over time technology, hardware, and software are rapidly changing CASE Tools CASE Tool Categories computer-assisted software engineering automated, microcomputer-based software packages for systems analysis and design increase analyst productivity facilitate communication among analysts and users provide continuity between life cycle phases helps integrate activities and processes upper CASE (also called front-end CASE) tools, used to perform analysis and design lower CASE (also called back-end CASE), used to generate computer language source code from CASE design integrated CASE, performing both upper and lower CASE functions Copyright 2005, Merrill Warkentin page 4

5 Upper CASE Lower CASE create and modify the system design store data in a project repository repository: collection of records, elements, diagrams, screens, reports, and other project information model organizational requirements and define system boundaries generate computer source code from the CASE design automated code generation may use several languages Advantages of Generating Code Traditional vs. CASE SDLC 27 time to develop new systems & maintain code decreases computer programs may be generated in more than one language CASE design may be purchased from third-party vendors and tailored to organizational needs generated code is free from program coding errors 28 Copyright Notice This document may not, in whole or part, be copied, photocopied, reproduced, translated, transmitted, or reduced to any electronic medium or machine readable form without explicit permission and written authorization from Dr. Merrill Warkentin. mwarkentin@acm.org MISProfessor.com Copyright 2005, Merrill Warkentin page 5