Chapter 14 Information System Development

Chapter 14 Objectives Explain the phases in the system development life cycle Describe how structured tools such as entity-relationship diagrams and dataflow diagrams are used in analysis and design Identify the guidelines for system development Recognize the responsibilities of various IT professionals Differentiate between packaged software and custom software Discuss the importance of project management, feasibility assessment, data and information gathering techniques, and documentation Identify program development as part of the system development life cycle Discuss techniques used to convert to a new system Next Understand how IT professionals support an information system p.14.2

What is the System Development Life Cycle? What is an information system (IS)? Set of hardware, software, data, people, and procedures that work together to produce information System Set of components that interact to achieve common goal Businesses use many types of systems Next p.14.2

What is the System Development Life Cycle? What is the system development life cycle (SDLC)? Next p.14. 2 Fig. 14-1

What is the System Development Life Cycle? What are guidelines for system development? Divide activities or tasks into phases Involve users Develop standards Sets of rules and procedures company expects employees to accept and follow Next p.14..3

What is the System Development Life Cycle? Who participates in the system development life cycle? data comm specialist steering committee programmers users vendors Webmaster systems analyst network engineer other system analysts data warehouse specialist management database specialist Next p.14. 4 Fig. 14-2

What is the System Development Life Cycle? What is a systems analyst? Responsible for designing and developing information system Liaison between users and IT professionals Converts user requests into technical specifications Next p.14.5

What is the System Development Life Cycle? What is the project team? Formed to work on project from beginning to end Consists of users, systems analyst, and other IT professionals Project leader Manages and controls project budget and schedule Next p.14.5

What is the System Development Life Cycle? What is project management? Process of planning, scheduling, and then controlling activities during SDLC responsibilities of project manager Establish goal, objectives, and expectations of the project, called the scope List required activities Determine time for each activity Give cost estimates for each activity Order activities List activities that can take place at the same time Next p.14.5

What is the System Development Life Cycle? What is a Gantt chart? Popular tool used to plan and schedule time relationships among project activities Next p.14.5 Fig. 14-3

What is the System Development Life Cycle? What is feasibility? Measure of how suitable system development will be to company four feasibility tests Operational feasibility Schedule feasibility Technical feasibility Economic feasibility also called cost/benefit feasibility Next p.14.6

What is the System Development Life Cycle? What are six data and information gathering techniques? Review documentation Observe Questionnaire One-on-one interview Joint (JAD) interview session Research Next p.14.7

What Initiates the System Development Life Cycle? What are some reasons to create or modify an information system? To correct problem in existing system To improve existing system Outside group may mandate change Competition can lead to change Next p.14.10

What Initiates the System Development Life Cycle? What is a request for system services? Users write formal request for new or modified information system Also called project request Next p.14.10 Fig. 14-7b

Planning Phase What is the planning phase? Begins when steering committee receives project request Function of committee: Review and approve project Prioritize requests Allocate resources Form project development team Next p.14.12

Analysis Phase What is the analysis phase? Consists of two major tasks Conduct preliminary investigation, also called feasibility study Perform detailed analysis 1. Study how current system works 2. Determine user’s wants, needs, and requirements 3. Recommend solution Next p.14.13

Entity-relationship diagrams Analysis Phase What is structured analysis and design? Entity-relationship diagrams Technique that attempts to address problem by using graphics and other tools Used to document findings in way everyone can understand Data flow diagrams Project dictionary Next p.14.15

Object in system that has data Analysis Phase What is an entity-relationship diagram (ERD)? Tool that graphically shows connections between entities in system Click to view Web Link then click Entity-Relationship Diagrams Entity Object in system that has data Next p.14.16 Fig. 14-10

Analysis Phase What is a data flow diagram (DFD)? Tool that graphically shows flow of data in system process data store data flows Click to view Web Link then click Data Flow Diagrams Next source p.14.17 Fig. 14-11

Analysis Phase What is a project dictionary? structured English Documentation and deliverables of project Helps keep track of huge amount of details in system decision tables decision trees data dictionary Click to view Web Link then click Project Dictionary Next p.14.17

Analysis Phase What is structured English? Used to explain details of process in project dictionary Next p.14.18 Fig. 14-12

Analysis Phase What is a decision table? Lists variety of conditions and actions that correspond to each condition Next p.14.18 Fig. 14-13

Analysis Phase What is a decision tree? Diagram that shows conditions and actions graphically Next p.14.18 Fig. 14-14

Analysis Phase What is a data dictionary? Stores name, description, and other details about each data item Next p.14.19 Fig. 14-15

Analysis Phase What is the system proposal? Assesses feasibility of each alternative solution At conclusion of analysis phase, system proposal presented to steering committee for approval Steering committee often must decide how system will be developed Buy packaged software from outside source? Build own custom software? Hire outside firm to handle more or all IT needs? Next p.14.19

Design Phase What is the design phase? Consists of two major activities Acquire hardware and software Develop all details of new or modified information system Next p.14.21

Design Phase What is needed to acquire new hardware and software? Talk with other systems analysts Identify all hardware and software requirements of new or modified system Visit vendors’ stores Surf the Web Read print and online trade journals, newspapers, and magazines Click to view video Next p.14.21

Design Phase What are three basic documents used to summarize technical specifications? Request for quotation (RFQ) Identifies product(s) you want Vendor quotes price(s) for listed product(s) Request for proposal (RFP) Vendor selects product(s) that meets your requirements and then quotes price(s) Request for information (RFI) Less formal method that uses standard form to request information about product or service Click to view Web Link then click Request for Proposal Next p.14.22

Design Phase What is a turnkey solution? Complete system provided by value-added reseller Next p.14.24 Fig. 14-19

Input and output design Design Phase What is detailed design? Database design Develop detailed design specifications for components in proposed solution Sometimes called physical design Input and output design Program design Next p.14.26

Design Phase What is a system flowchart? Documents relationships among programs in process Shows how other elements of system interact with major process Next p.14.28 Fig. 14-24

Design Phase What is a prototype? Working model of proposed system Rapid application development (RAD) Process of developing applications with prototypes Next p.14.28

Design Phase What is computer-aided software engineering (CASE)? Project repository Stores diagrams, specifications, descriptions, programs, and any other deliverable generated Software tools designed to support one or more SDLC activities Graphics Enables drawing of diagrams Prototyping Creates models of proposed system Quality assurance Analyzes deliverables for accuracy Click to view Web Link then click CASE Products Code generators Create actual computer programs from design specifications Housekeeping Establishes user accounts and provides backup and recovery functions Next p.14.29

What is a structured walkthrough? Design Phase What is a structured walkthrough? Step-by-step review by project team and users of any SDLC deliverable Used to review detailed design specifications before they are given to programming team Next p.14.30

Install and test new system Implementation Phase What is the implementation phase? Purpose is to construct, or build, new or modified system and then deliver it to users Develop programs Install and test new system Convert to new system Train users Next p.14.30

Implementation Phase What is the program development life cycle (PDLC)? Analyze problem Programmers write programs as per specifications They follow an organized set of activities known as PDLC Design programs Code programs Test programs Formalize solution Next Maintain programs p.14.30

Implementation Phase What are the three types of tests performed by system developers? Systems test Verifies all programs in application work together properly Acceptance Test Performed by end-users; checks that new system works with actual data Integration Test Verifies application works with other applications Next p.14.30

Implementation Phase What is training? Showing users exactly how they will use new hardware and software in system Next p.14.31 Fig. 14-26

Implementation Phase What are conversion strategies? Used to change from old system to new system Next p.14.31 Fig. 14-27

Support Phase What is the support phase? Provides ongoing assistance after system is implemented Conduct a post-implementation system review Identify errors Monitor system performance Identify enhancements Next p.14.32

Summary of Information System Development What is the system development life cycle? What initiates the system development life cycle? Planning phase Analysis phase Design phase Implementation phase Support phase Chapter 14 Complete