Information systems analysis and design
The process of developing and maintaining an information system
System
A group of interrelated procedures used for a business function, with an identifiable boundary, working together for some purpose
Characteristics of a system
Components, interrelated components, boundary, purpose, environment, interfaces, constraints, input, output
System Concepts
Decomposition, modularity, coupling, cohesion
Decomposition
The process of breaking the description of a system down into small components, aka functional decomposition
Modularity
Dividing a system up into chunk or modules of a relatively uniform size
Coupling
The extent to which subsystems depend on each other
Cohesion
The extent to which a system or subsystem performs a single function
Systems development methodology
Organizations use this standard set of steps to develop and support their information systems
Systems Development Life Cycle
Series of steps used to mark the phases of development for an information system
Steps of SDLC
Planning and selection, analysis, design, implementation and operation
Systems Planning Phase
Project initiation - Prepare system request and perform preliminary feasibility analysis
Set up the project - Project plan, including work plan and staffing plan
Analysis Phase
Determine analysis strategy by studying the existing system and its problems
Collect and analyze requirements - develop new system concept and describe new system with analysis models
Prepare and present system proposal - summarize results of the analysis
Design Phase
Determine design strategy - build/buy/outsource
Design system components - Architecture, interface, database, programs. Assemble design elements into system specification
Present to steering committee - Yes or no decision is made before entering final pha
Implementation Phase
System construction - programming and testing
System installation - Training and conversion to new system
On-going system support
How do systems get built?
Plan project, system requirements, system specifications, obsolete system, new project laucnehs
Systems analyst roles
Key role in developing information systems - Analyzing the business situation, identifying opportunities for improvements, and designing an information system to implement the improvements
Systems analyst roles
Interaction with an array of people - Technical specialists, (DBAs, network admins, programmers) business people, (users, managers, steering committee) others (vendors, consultants)
Systems analyst roles
Variety of specialized roles -
1. People-oriented: Change management analyst, project management
2. Business-oriented: Requirements analyst, business analyst
3. Technically-oriented: Infrastructure analyst
4. Generalist: systems analyst
Alternative approaches to development
Prototyping, Rapid application development (RAD), computer-assisted software engineering (CASE) tools, joint application design, participatory design, agile methodology
IT Projects are prone to high failure rates
Solution is proper methodology for systems analysis and design. EX: The environment of a school includes prospective students, foundations and funding agencies, and the news media
Systems analyst roles
Problem solver that guides the project through the different phases of the SDLC
Components
An irreducible part or aggregation of parts that makes up a system; also called a subsystem. Within a company, the system can be decomposed into payroll subsystem, inventory subsystem, etc.
Boundary
The line that marks the inside and outside of a system and that sets off the system from its environment. Components within the boundary can be changed, whereas systems outside the boundary cannot be changed
Environment
Everything external to a system that interacts with the system.
Constraints
A limit to what a system can accomplish. Some of these constraints are imposed inside the system(a limited number of staff available), and others are imposed by the environment(Due dates or regulations)
Output
The system takes input from outside, processes it, and sends the resulting output back to its environment
Input
The system takes input from outside, processes it, and sends the resulting output back to its environment
Interfaces
Point of contact where a system meets its environment or where subsystems meet each other
Purpose
The overall goal or function of a system
Interrelated Components
Dependence of one part of the system on one or more other system parts. EX: The work of one component, such as producing a daily report of customer orders, may not progress successfully until the work of another component is finished, such as sorting cust
Projects are identified by
Top management, steering committee, user departments, development group, IS staff
Top-down identification
Senior management or steering committee. Focus is on global needs of organization
Bottom-up identification
Business unit or IS group. Do not reflect overall goals of the organization
Document development projects
Factors: perceived needs of the organization, existing systems and ongoing projects, resource availability, evaluation criteria, current business conditions, perspectives of the decision makers
Baseline project plan
Internal document - Introduction, system description, feasibility assessment, management issues
Project scope statement
Prepared for external and internal stakeholders. Provides a high-level overview of the project
PSS
A document prepared for the customer that describes what the project will deliver and outlines generally at a high level all work required to complete the project. Easy document to create because it typically consists of a high-level summary of the BPP
PSS Sections
General project information, problem/opportunity statement, project objectives, project description, business benefits, project deliverables, estimated project duration
Objectives of the selection process
Assure conformity to organizational standards, all parties agree to continue with project
Project identification
Top-down identification or bottom-up identification. Deliverable: System service request
Present the project, its output, and tasks required to complete the work. Feasibility analysis. Deliverables: Internally- BPP, Externally-PSS
Project selection
Walkthrough process -> decision
Walkthrough
Peer group review. Walkthrough review form, individuals polled, walkthrough action list
Factors influencing the deciison
Perceived and real needs, existing and available resources, current business conditions, evaluation criteria, list of potential and ongoing projects
Categories of feasibility
Economic, operational, technical, schedule, legal and contractual, political
Economic feasibility
Assessment of how a system is a positive financial investment
Operational feasibility
Assessment of how a system solves business problems or takes advantage of opportunities
Technical feasibility
Assessment of the development organizations ability to construct a system
Schedule feasibility
Assessment of time-frame and project completion dates with respect to organization constraints for affecting change
Legal and Contractual Feasibility
Assessment of legal and contractual ramifications of new system
Political feasibility
Assessment of key stakeholders view in organization toward proposed system
Cost-benefit analysis
Determine tangible and intangible benefits
Open ended question vs close ended
Open ended questions start a discussion, no pre-specified answer and are used to probe for unanticipated answers. Close ended questions you give the possible answers and it has to be one of them
Tangible benefits
Cost reduction or avoidance, error reduction, increased flexibility, increased speed of activity, improvement in management or control
One-time costs
Development costs, new hardware, user training, site preparation, new software
Recurring costs
Application software maintenance, incremental data storage required, incremental communications, new software or hardware leases, supplies
Observation of workers
Observe workers at selected times to see how data are handled
Business Documents and procedures
Study documents to discover reported issues, policies, rules and directions as well as concrete examples of the use of data and information in the organization
Types of info to be discovered - problems with existing system, opportunity to meet new trend,
Joint application design
Put all the actors of the system in the same room and brainstorm about the system requirements. Collect system requirements from key people. Conducted off site
Cost benefit analysis techniques
Net present value, return on investment, break-even analysis
Prototyping
User quickly converts requirements to working version of the system. Useful when the customer cannot express what they want
Business Process Reengineering (BPR)
Search for and implementation of radical change in processes to achieve breakthrough improvements in products and services
Modern techniques to find requirements
Joint application design and prototyping
Information systems analysis and design
The process of developing and maintaining an information system
System
A group of interrelated procedures used for a business function, with an identifiable boundary, working together for some purpose
Characteristics of a system
Components, interrelated components, boundary, purpose, environment, interfaces, constraints, input, output
System Concepts
Decomposition, modularity, coupling, cohesion
Decomposition
The process of breaking the description of a system down into small components, aka functional decomposition
Modularity
Dividing a system up into chunk or modules of a relatively uniform size
Coupling
The extent to which subsystems depend on each other
Cohesion
The extent to which a system or subsystem performs a single function
Systems development methodology
Organizations use this standard set of steps to develop and support their information systems
Systems Development Life Cycle
Series of steps used to mark the phases of development for an information system
Steps of SDLC
Planning and selection, analysis, design, implementation and operation
Systems Planning Phase
Project initiation - Prepare system request and perform preliminary feasibility analysis
Set up the project - Project plan, including work plan and staffing plan
Analysis Phase
Determine analysis strategy by studying the existing system and its problems
Collect and analyze requirements - develop new system concept and describe new system with analysis models
Prepare and present system proposal - summarize results of the analysis
Design Phase
Determine design strategy - build/buy/outsource
Design system components - Architecture, interface, database, programs. Assemble design elements into system specification
Present to steering committee - Yes or no decision is made before entering final pha
Implementation Phase
System construction - programming and testing
System installation - Training and conversion to new system
On-going system support
How do systems get built?
Plan project, system requirements, system specifications, obsolete system, new project laucnehs
Systems analyst roles
Key role in developing information systems - Analyzing the business situation, identifying opportunities for improvements, and designing an information system to implement the improvements
Systems analyst roles
Interaction with an array of people - Technical specialists, (DBAs, network admins, programmers) business people, (users, managers, steering committee) others (vendors, consultants)
Systems analyst roles
Variety of specialized roles -
1. People-oriented: Change management analyst, project management
2. Business-oriented: Requirements analyst, business analyst
3. Technically-oriented: Infrastructure analyst
4. Generalist: systems analyst
Alternative approaches to development
Prototyping, Rapid application development (RAD), computer-assisted software engineering (CASE) tools, joint application design, participatory design, agile methodology
IT Projects are prone to high failure rates
Solution is proper methodology for systems analysis and design. EX: The environment of a school includes prospective students, foundations and funding agencies, and the news media
Systems analyst roles
Problem solver that guides the project through the different phases of the SDLC
Components
An irreducible part or aggregation of parts that makes up a system; also called a subsystem. Within a company, the system can be decomposed into payroll subsystem, inventory subsystem, etc.
Boundary
The line that marks the inside and outside of a system and that sets off the system from its environment. Components within the boundary can be changed, whereas systems outside the boundary cannot be changed
Environment
Everything external to a system that interacts with the system.
Constraints
A limit to what a system can accomplish. Some of these constraints are imposed inside the system(a limited number of staff available), and others are imposed by the environment(Due dates or regulations)
Output
The system takes input from outside, processes it, and sends the resulting output back to its environment
Input
The system takes input from outside, processes it, and sends the resulting output back to its environment
Interfaces
Point of contact where a system meets its environment or where subsystems meet each other
Purpose
The overall goal or function of a system
Interrelated Components
Dependence of one part of the system on one or more other system parts. EX: The work of one component, such as producing a daily report of customer orders, may not progress successfully until the work of another component is finished, such as sorting cust
Projects are identified by
Top management, steering committee, user departments, development group, IS staff
Top-down identification
Senior management or steering committee. Focus is on global needs of organization
Bottom-up identification
Business unit or IS group. Do not reflect overall goals of the organization
Document development projects
Factors: perceived needs of the organization, existing systems and ongoing projects, resource availability, evaluation criteria, current business conditions, perspectives of the decision makers
Baseline project plan
Internal document - Introduction, system description, feasibility assessment, management issues
Project scope statement
Prepared for external and internal stakeholders. Provides a high-level overview of the project
PSS
A document prepared for the customer that describes what the project will deliver and outlines generally at a high level all work required to complete the project. Easy document to create because it typically consists of a high-level summary of the BPP
PSS Sections
General project information, problem/opportunity statement, project objectives, project description, business benefits, project deliverables, estimated project duration
Objectives of the selection process
Assure conformity to organizational standards, all parties agree to continue with project
Project identification
Top-down identification or bottom-up identification. Deliverable: System service request
Present the project, its output, and tasks required to complete the work. Feasibility analysis. Deliverables: Internally- BPP, Externally-PSS
Project selection
Walkthrough process -> decision
Walkthrough
Peer group review. Walkthrough review form, individuals polled, walkthrough action list
Factors influencing the deciison
Perceived and real needs, existing and available resources, current business conditions, evaluation criteria, list of potential and ongoing projects
Categories of feasibility
Economic, operational, technical, schedule, legal and contractual, political
Economic feasibility
Assessment of how a system is a positive financial investment
Operational feasibility
Assessment of how a system solves business problems or takes advantage of opportunities
Technical feasibility
Assessment of the development organizations ability to construct a system
Schedule feasibility
Assessment of time-frame and project completion dates with respect to organization constraints for affecting change
Legal and Contractual Feasibility
Assessment of legal and contractual ramifications of new system
Political feasibility
Assessment of key stakeholders view in organization toward proposed system
Cost-benefit analysis
Determine tangible and intangible benefits
Open ended question vs close ended
Open ended questions start a discussion, no pre-specified answer and are used to probe for unanticipated answers. Close ended questions you give the possible answers and it has to be one of them
Tangible benefits
Cost reduction or avoidance, error reduction, increased flexibility, increased speed of activity, improvement in management or control
One-time costs
Development costs, new hardware, user training, site preparation, new software
Recurring costs
Application software maintenance, incremental data storage required, incremental communications, new software or hardware leases, supplies
Observation of workers
Observe workers at selected times to see how data are handled
Business Documents and procedures
Study documents to discover reported issues, policies, rules and directions as well as concrete examples of the use of data and information in the organization
Types of info to be discovered - problems with existing system, opportunity to meet new trend,
Joint application design
Put all the actors of the system in the same room and brainstorm about the system requirements. Collect system requirements from key people. Conducted off site
Cost benefit analysis techniques
Net present value, return on investment, break-even analysis
Prototyping
User quickly converts requirements to working version of the system. Useful when the customer cannot express what they want
Business Process Reengineering (BPR)
Search for and implementation of radical change in processes to achieve breakthrough improvements in products and services
Modern techniques to find requirements
Joint application design and prototyping