Building and Managing Systems Chapter Thirteen (10E)

9/15/20152 Overview of Systems Development  Systems development - activities that go into producing an information systems solution to an organization problem or opportunity –structured type of problem solving with distinct activities  These activities are present to some extent for all of the different ways of developing systems described later

9/15/20153 System Development Process  Systems analysis  System design  Programming  Testing  Conversion  Production & maintenance

9/15/20154 Phases of the Systems Development AnalysisDesign Programming & Testing Conversio n Prod&Maintenance Investigatio n Requireme nts to component s Training Feasibility Feasibility Evaluate Evaluate alternative s Conversion Requiremen ts definition

9/15/20155 Systems Analysis  Definition - analysis of problem to be solved with an information system  Major tasks –Understand the problem  Define the problem  Identify causes  Specify solutions –Feasibility study: can problem be solved within constraints? –Establishing information requirements for end users  Deliverables include system proposal, feasibility study, user requirements  Approval by management to proceed  Role of the end user

9/15/20156 Feasibility  Technical: assess hardware, software, technical resources  Economic: will benefits outweigh costs  Operational: Is solution desirable within existing conditions?

9/15/20157 Systems Design  Definition - details how a system will meet the information requirements determined by systems analysis  Designer responsibilities –consider alternate technologies –manage and control the technical realization of the system –Translate the system requirements into specifications that will deliver a system that solves the problems determined in systems analysis  Role of end users in systems design

9/15/20158 Examples of Translation of Requirements into Specifications in the Design Phase  Design of input files (usually database tables)  Procedures (the formulas or algorithms that will be used to process the inputs into outputs)  Output files (the files that will contain the processed data, or the files that record input from customers, employees, suppliers, etc.)  User interface (the design of windows, menus, icons, drop down lists, etc.)  Interfaces (determination of how the system will interact with other systems; inputs from other systems, outputs to other systems)

9/15/20159 Additional Design Specifications  OUTPUT –MEDIUM; CONTENT; TIMING  INPUT –ORIGINS; FLOW; DATA ENTRY  USER INTERFACE –SIMPLICITY; EFFICIENCY; LOGIC –FEEDBACK; ERRORS  DATABASE DESIGN –LOGICAL DATA RELATIONS –VOLUME, SPEED REQUIREMENTS –FILE ORGANIZATION & DESIGN –RECORD SPECIFICATIONS

9/15/ Designer Specifications  PROCESSING –COMPUTATIONS –PROGRAM MODULES –REQUIRED REPORTS –TIMING OF OUTPUTS  MANUAL PROCEDURES –WHAT ACTIVITIES –WHO PERFORMS THEM –HOW –WHERE

9/15/ Designer Specifications  CONVERSION –TRANSFER FILES –INITIATE NEW PROCEDURES –SELECT TESTING MODULES –CUT OVER TO NEW SYSTEM  TRAINING –SELECT TRAINING TECHNIQUES –DEVELOP TRAINING MODULES –IDENTIFY TRAINING FACILITIES  ORGANIZATIONAL CHANGES –TASK REDESIGN –JOB DESIGN –PROCESS DESIGN –OFFICE / ORGANIZATION STRUCTURE DESIGN –REPORTING RELATIONSHIPS *

9/15/ Role Of End Users in Analysis and Design  Users drive systems effort  Must have sufficient control to ensure system reflects business priorities and needs  Functional users drive system information requirements  Users can play an important role in the design effort (see preceding slides)

9/15/ Completing System Development Process  Programming: Translating needs to Program Code  Testing: Does System Produce Desired Results? –Unit testing: Tests Each Unit Separately –System testing: Do Modules Function as planned? –Acceptance testing: Final Certification –Test plan: Preparations for Tests to be Performed  Role of the end user in testing

9/15/ Conversion  Strategies for conversion –Parallel: Old & New Run Same Problems. Give Same Results? –Direct: Risky Conversion to New System –Pilot: Introduce Into One Area. Does it Work? Yes: Introduce into Other Area –Phased: Introduce in Stages  Training and Documentation  Role of end users in conversion

9/15/ Production & Maintenance  Production: Constant Review by Users & Operators. Does the system meet its goals?  Maintenance: Upkeep; Update; Corrections Over Time –Fix problems not discovered during earlier stages –Make changes to the system dictated by new requirements

9/15/ SYSTEMS DEVELOPMENT CORE ACTIVITY CORE ACTIVITY DESCRIPTION DESCRIPTION SYSTEMS ANALYSIS IDENTIFY PROBLEM(S) SPECIFY PROBLEM ESTABLISH INFORMATION REQUIREMENTS SYSTEMS DESIGN CREATE LOGICAL DESIGN SPECIFICATIONS CREATE PHYSICAL DESIGN SPECIFICATIONS MANAGE TECHNICAL REALIZATION OF SYSTEM PROGRAMMING TRANSLATE DESIGN INTO CODE TESTING UNIT SYSTEMS ACCEPTANCE CONVERSION PLAN PREPARE DOCUMENTATION TRAIN USERS & TECHNICAL STAFF PRODUCTION & MAINTENANCE OPERATE EVALUATE MODIFY

9/15/ Five Methods to Build Systems  Five methods –Systems Life Cycle –Prototyping –Application Software –End-user Development –Outsourcing  Each method has the six general steps described in the systems development process

9/15/ Stages of the Systems Life Cycle  Oldest method  Stages correspond to the stages of systems development described earlier  Birth, maturity, death (the cycle repeats)  Used for TPS, MIS, or large complex systems  Formal process, controls, deliverables  Limitations –Resource intensive (time and money) –Inflexible and inhibits change (freezing of specifications) –Ill-suited for decision-oriented applications or situations where system requirements are vague

9/15/ Prototyping  Definition - process of building an experimental system quickly and inexpensively for demonstration and evaluation so that end users can better determine information requirements  Iterative design  Very informal compared to SLC – requirements are determined dynamically instead of frozen in advance –No distinct phases –No distinct intermediate deliverables for management

9/15/ Identify user needs Develop a prototype Use the prototype Y N Prototype acceptable ? Development of a Prototype

9/15/ The Attraction of Prototyping  Prototyping is useful when user requirements are uncertain, developing user interfaces, or developing interactive applications with multiple screens  Communications between the systems analyst and user are improved.  The user plays a more active role in system development.  Implementation is much easier because the user knows what to expect.

9/15/ Potential Pitfalls of Prototyping  The haste to deliver the prototype may produce shortcuts in problem definition, alternative evaluation, and documentation.  The users may get so excited about the prototype that they have unrealistic expectations of the operational system.  The computer-human interface provided by certain prototyping tools may not reflect good design techniques.

9/15/ Applications Software Packages  Definition - set of programs that are available for sale or lease  Packages eliminate the need for writing programs when building systems; also reduces design, programming, testing, conversion and maintenance work  When are they appropriate? –common functions –limited resources for in-house development –desktop applications for end users

9/15/ Types of Prepackaged Software  Accounts payable  Accounts receivable  Check processing  Document imaging  Forecasting and modeling  General ledger  Health insurance  Hotel management  Human resources  Job accounting  Inventory control  Job costing  Mailing labels  Order entry  Payroll  Process control  Route scheduling  Sales and distribution  Stock management  Tax accounting

9/15/ Advantages/Disadvantages of Packages  Advantages –Speed up of systems development phases –Periodic enhancements/updates from the vendor (reduced maintenance) –External work is often perceived as superior –Software costs appear to be fixed  Disadvantages –Packages never satisfy all user requirements (70% is very good) –costs of customization

9/15/ End-User Development  Definition - the development of information systems by end users with little or no formal assistance from technical specialists  End user tools - query languages, report generators, graphics languages, applications generators, or microcomputer tools

9/15/ End-User Development  Definition - the development of information systems by end users with little or no formal assistance from technical specialists  End user tools - query languages, report generators, graphics languages, applications generators, or microcomputer tools

9/15/ Historical Factors That Encouraged End User Application Development  The programming backlog  The widespread use of PCs  The emergence of 4GLs (spreadsheets, query languages, and report generators)  Increasing popularity of client/server architecture

9/15/ Typical End User Applications  Use of spreadsheets  Management graphics  Word processing (mail merge)  Queries and report generation  Desktop publishing   Creating local databases  Using external databases  Calendaring, meeting management, and personal support

9/15/ Benefits and Risks of EUC  Benefits –Quicker development –Good fit to needs –Efficient utilization –Acquisition of skills –Free IS staff time  Risks –Poor documentation –Lack of quality assurance standards and controls –Islands of information –Duplication of effort –Security problems

9/15/ Outsourcing Information Systems  Definition - the practice of contracting computer center operations, telecommunications networks, or application development to external vendors. Older usage of this term meant hiring an outside firm to develop a custom system.  Outsourcing is big business; IBM, AT&T, EDS, big accounting firms are all major outsourcers

9/15/ Newer Methodologies  Newer methodologies –Joint application development (JAD) –Rapid application development (RAD)  Characteristics –Attempts to speed development by reducing documentation involved in SDLC –Large amounts of prototyping –Heavy involvement of end users throughout project –End users often take leadership roles –Does not skip analysis stage like prototyping –Lots of team meetings where users and IS professionals work together –Use of many new tools (e.g., Visual Basic, Java, C#, collaborative software, reusable software)