Systems Development Life Cycle •The Analysis Phase •Introduction to process modelling
What is the System Development Cycle? What is an information system (IS)?
Hardware, software, data, people, and procedures that work together to produce quality information
System—Set of components that interact to achieve common goal Businesses use many types of systems
What is the System Development Cycle? What are the phases of the system development cycle? Phase 2. Analysis
Phase 1. Planning
Review project requests Prioritize project requests Allocate resources Identify project development team
Conduct preliminary investigation Perform detailed analysis activities: Study current system Determine user requirements Recommend solution
Phase 5. Support
Conduct post-implementation system review Identify errors and enhancements Monitor system performance
Phase 3. Design
Acquire hardware and software, if necessary Develop details of system
Phase 4. Implementation
Develop programs, if necessary Install and test new system Train users Convert to new system Next
What is the System Development Cycle? What are guidelines for system development?
Arrange tasks into phases (groups of activities) Involve users (anyone for whom system is being built)
Develop clearly defined standards (procedures company expects employees to follow) Next
What is the System Development Cycle? Who participates in the system development life cycle?
What is the System Development Cycle? What is a systems analyst? Responsible for designing and developing information system Liaison between users and IT professionals
What is the System Development 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—one member of the team who manages and controls project budget and schedule
What is the System Development Cycle? What is project management?
Process of planning, scheduling, and controlling activities during system development cycle Project leader identifies elements for project
Goal, objectives, and expectations, collectively called scope
Time estimates for each activity
Cost estimates for each activity
Order of activities
Activities that can take place at same time
What is the System Development Cycle? What is a Gantt chart?
Popular tool used to plan and schedule time relationships among project activities
What is the System Development Cycle? What is project management software?
Program (such as Microsoft Office Project 2003) used by project leaders to plan, schedule, and control projects
What is the System Development Cycle? What is feasibility? Operational feasibility
Measure of how suitable system development will be to the company
Four feasibility tests: Schedule feasibility
Economic feasibility (also called cost/benefit feasibility)
What is the System Development Cycle? What is documentation? Collection and summarization of data and information Includes reports, diagrams, programs, and other deliverables Project notebook contains all documentation for single project
What is the System Development Cycle? What are six data and information gathering techniques?
Review documentation Observe Questionnaire Interview Joint-application design (JAD) session Research Next
What Initiates the System Development 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
What Initiates the System Development Cycle? What is a request for system services?
Formal request for new or modified information system
Also called project request
Planning Phase What is the planning phase? Begins when steering committee receives project request Steering committee— decision-making body for the company
Function of committee: Review and approve project requests
Prioritize project requests
Form project development team for each approved project Next
Analysis Phase What is the analysis phase?
Conduct preliminary investigation, also called feasibility study
Perform detailed analysis
Analysis Phase What is the preliminary investigation? Determine exact nature of problem or improvement and whether it is worth pursuing
Findings are presented in feasibility report, also known as a feasibility study
Analysis Phase What is detailed analysis? 1. Study how current system works 2. Determine user’s wants, needs, and requirements
3. Recommend solution
Sometimes called logical design Next
Analysis Phase What is process modeling? Technique that describes processes that transform inputs into outputs Also called structured analysis and design
Three tools used for process modeling
Data flow diagrams Project dictionary
Analysis Phase What is an entity-relationship diagram (ERD)?
Tool that graphically shows connections between entities in system
Analysis Phase What is a data flow diagram (DFD)?
Tool that graphically shows flow of data in system
Analysis Phase What is a project dictionary? Contains all the documentation and deliverables of project
Helps keep track of huge amount of details in system
Variety of techniques to enter items in project dictionary Structured English Decision tables Decision trees Data dictionary Next
Analysis Phase What is Structured English?
Used to explain details of process in project dictionary
Analysis Phase What is a decision table?
Lists variety of conditions and actions that correspond to each condition
Analysis Phase What is a decision tree?
Shows conditions and actions graphically
Analysis Phase What is a data dictionary?
Stores name, description, and other details about each data item
Analysis Phase What is object modeling? Combines data with the processes that act on data into single unit called an object
Object—an item that can contain both data and procedures that read or manipulate the data
Sometimes called object-oriented (OO) analysis and design Uses Unified Modeling Language (UML)—graphical tool for documenting system Next
Analysis Phase What is a use case diagram?
Graphically shows how actors interact with information system
Actor—user or other entity Use case— function that actor can perform
Analysis Phase What is a class diagram?
Graphically shows classes and subclasses in system
Class is group of objects— Can have lower levels called subclasses
Analysis Phase What is the system proposal?
Assesses feasibility of each alternative solution
Recommends the most feasible solution for the project
Presented to steering committee, which decides how system will be developed
Analysis Phase What are possible software solutions?
Horizontal market software—meets needs of many companies
Buy packaged software—prewritten software available for purchase Write own custom software—software developed at user’s request
Vertical market software—designed for particular industry
Outsource—have outside source develop software Next