Unit 1 Flashcards
define information systems analysis and design
Information Systems Analysis and Design
Complex organizational process
Used to develop and maintain computer-based information systems
Used by a team of business and systems professionals
Define Application Software
Computer software designed to support organizational functions or processes
define Systems Analyst
Systems Analyst
Organizational role most responsible for analysis and design of information systems
How has the approach to systems analysis and design changed since the 1950s-90s?
A Modern Approach to Systems Analysis and Design
1950s: focus on efficient automation of existing processes
1960s: advent of procedural third generation languages (3GL) faster and more reliable computers
1970s: system development becomes more like an engineering discipline
1980s: major breakthrough with 4GL, CASE tools, object-oriented methods
1990s: focus on system integration, GUI applications, client/server platforms, Internet
The new century: Web application development, wireless PDAs and smart phones, component-based applications, application service providers (ASP)
What is system development methodology
Developing Information Systems
System Development Methodology is a standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems.
What is the SDLC?
Systems Development Life Cycle (SDLC)
Traditional methodology used to develop, maintain, and replace information systems
What are the phases in the SDLC
Phases in SDLC: Planning Analysis Design Implementation Maintenance
What is the planning phase?
Systems Development Life Cycle (SDLC) (Cont.)
Planning – an organization’s total information system needs are identified, analyzed, prioritized, and arranged
what is design phase?
Design – a description of the recommended solution is converted into logical and then physical system specifications
What is the analysis phase?
Analysis – system requirements are studied and structured
What is the differences and similarities to logical design and physical design?
Logical design – all functional features of the system chosen for development in analysis are described independently of any computer platform
Physical design – the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished
What is physical design
the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished
what is logical design
all functional features of the system chosen for development in analysis are described independently of any computer platform
what is the implementation phase
Implementation – the information system is coded, tested, installed and supported in the organization
Maintenance – an information system is systematically repaired and improved
What is the maintenance phase
an information system is systematically repaired and improved
What is the waterfall effect of the sdlc?
that one phase does not begin until the previous completes with very little backtracking
What are problems with the waterfall approach?
Problems with Waterfall Approach
Feedback ignored, milestones lock in design specs even when conditions change
Limited user involvement (only in requirements phase)
Too much focus on milestone deadlines of SDLC phases to the detriment of sound development practices
What are the different approaches to improving development?
Different Approaches to Improving Development CASE Tools Rapid Application Development (RAD) Agile Methodologies eXtreme Programming
What are case tools?
Computer-Aided Software Engineering (CASE) Tools
Diagramming tools enable graphical representation.
Computer displays and report generators help prototype how systems “look and feel”.
IBM’s Rational products are the best known CASE tools.
Analysis tools automatically check for consistency in diagrams, forms, and reports.
Documentation generators standardize technical and user documentation.
Code generators enable automatic generation of programs and database code directly from design documents, diagrams, forms, and reports.
A central repository provides integrated storage of diagrams, reports, and project management specifications.
what is RAD
Rapid Application Development (RAD)
Decreases design and implementation time
Involves: extensive user involvement, prototyping, integrated CASE tools, code generators
More focus on user interface and system function, less on detailed business analysis and system performance
What are agile methodologies
Agile Methodologies
Motivated by recognition of software development as fluid, unpredictable, and dynamic
What are the 3 key principles of agile methodologies
Three key principles
Adaptive rather than predictive
Emphasize people rather than roles
Self-adaptive processes
When should you use agile methodologies
When to use Agile Methodologies If your project involves: Unpredictable or dynamic requirements Responsible and motivated developers Customers who understand the process and will get involved
what is extreme programming
eXtreme Programming Short, incremental development cycles Automated tests Two-person programming teams Coding, testing, listening, designing Coding and testing operate together
what are the advantages to extreme programming
Advantages:
Communication between developers
High level of productivity
High-quality code
what is OOAD
Object-Oriented Analysis and Design (OOAD)
Based on objects rather than data or processes
Object: a structure encapsulating attributes and behaviors of a real-world entity
Object class: a logical grouping of objects sharing the same attributes and behaviors
Inheritance: hierarchical arrangement of classes enable subclasses to inherit properties of superclasses
What is RUP
An object-oriented systems development methodology
Establishes four phase of development: inception, elaboration, construction, and transition
Each phase is organized into a number of separate iterations.
what is our approach to systems
Our Approach to Systems Development
The SDLC is an organizing and guiding principle in this book.
We may construct artificial boundaries or artificially separate activities and processes for learning purposes.
Our intent is to help you understand all the pieces and how to assemble them.
what is a tangible cost
Tangible cost: a cost associated with an information system that can be measured in dollars and with certainty
what are IS development tangible costs
hardware, labor, operational, employee training etc
define intangible cost
Intangible cost: a cost associated with an information system that cannot be easily measured in terms of dollars or with certainty
intangible costs include?
Intangible costs can include:
Loss of customer goodwill,
Employee morale, or
Operational inefficiency.
what is a one time cost
One-time cost: a cost associated with project start-up and development or system start-up
What activities are encompassed by one time costs
These costs encompass activities such as: Systems development, New hardware and software purchases, User training, Site preparation, and Data or system conversion.
define recurring costs
Recurring cost: a cost resulting from the ongoing evolution and use of a system
give examples of recurring costs
Examples of these costs include: Application software maintenance Incremental data storage expenses Incremental communications New software and hardware leases, and Supplies and other expenses (i.e., paper, forms, data center personnel).
which costs can be both fixed or variable in nature
Both one-time and recurring costs can consist of items that are fixed or variable in nature.
define TVM
Time value of money (TVM): the concept that money available today is worth more than the same amount tomorrow
what is a discount rate
Discount rate: the rate of return used to compute the present value of future cash flows (the cost of capital)
What is a present value
Present value: the current value of a future cash flow
What are fixed costs? give example
Fixed costs are billed or incurred at a regular interval and usually at a fixed rate.
Example: facility lease payment
What are variable costs, give an example
Variable costs are items that vary in relation to usage.
Example: long-distance charges
define NPV
Net Present Value (NPV)
Use discount rate to determine present value of cash outlays and receipts
Define BEA
Break-Even Analysis (BEA)
Amount of time required for cumulative cash flow to equal initial and ongoing investment
define ROI
Return on Investment (ROI)
Ratio of cash receipts to cash outlays
What is time value of money?
Used with all three cost-effectiveness techniques.
Concept that recognizes that a dollar today is worth more than a dollar one year from now.
Invest $100 at 2% for one year yields $102.
So $100 today and $102 one year from today represent the same value.
Given $20,000 benefit from information system two years from now and 10% return from other investments, means that benefit is worth $16,528 today.
define payback analysis
Payback analysis – a technique for determining if and when an investment will pay for itself
Define payback period
Payback period – the period of time that will lapse before accrued benefits overtake accrued and continuing costs.
define present value
Present value – the current value of a dollar at any time in the future.
PVn = 1/(1 + i)n
Where n is the number of years and i is discount rate
what is the discount rate for a business
Discount rate – a percentage similar to interest rates that you earn on your savings.
In most cases the discount rate for a business is the opportunity cost of being able to invest money in other projects or investments
define ROA
Return-on-Investment (ROA) analysis – a technique that compares the lifetime profitability of alternative solutions.
The ROI for a solution or project is a percentage rate that measures the relationship between the amount the business gets back from an investment and the amount invested.
equation for lifetime ROI
Lifetime ROI = (estimated lifetime benefits – estimated lifetime costs) / estimated lifetime costs
Equation for annual ROI
Annual ROI = lifetime ROI / lifetime of the system
what is PVn and NPV
Net Present Value
PVn = present value of Y dollars n years from now based on a discount rate of i.
NPV = sum of PVs across years.
Calculates time value of money
define tangible benefits with examples
Tangible benefits refer to items that can be measured in dollars and with certainty. Examples include: reduced personnel expenses lower transaction costs, or higher profit margins.
tangible benefits include which categories
Most tangible benefits will fit within the following categories:
Cost reduction and avoidance
Error reduction
Increased flexibility
Increased speed of activity
Improvement of management planning and control
Opening new markets and increasing sales opportunities
what are intangible benefits
Intangible benefits are benefits derived from the creation of an information system that cannot be easily measured in dollars or with certainty.
May have direct organizational benefits, such as the improvement of employee morale
May have broader societal implications, such as the reduction of waste creation or resource consumption
define legal feasibility
Copyrights Union contracts Legal requirements for financial reporting Antitrust laws National data and work laws
economic feasibility during scope, problem, and decision analysis?
During Scope Definition
Do the problems or opportunities warrant the cost of a detailed study and analysis of the current system?
During Problem Analysis
After a detailed study of the current system
Better estimates of development costs and benefits
During Decision Analysis
Requirements now defined
Development costs can be better estimated
what is schedule feasibility
Schedule feasibility
Are specified deadlines mandatory or desirable?
Are mandatory deadlines realistic for proposed solution?
what is technical feasibility
Is the proposed technology or solution practical?
Do we currently possess the necessary technology?
Do we possess the necessary technical expertise?
cultural feasibility
Does management support the system?
How do end users feel about their role in the system?
What end users may resist or not use the system? How can this be overcome?
How will the working environment change? Can users and management adapt to the change?
operational feasibility
How well proposed system solves the problems and takes advantage of opportunities identified during the scope definition and problem analysis phases
How well proposed system satisfies system requirements identified in the requirements analysis phase
Is the problem still worth solving
what are feasibility concerns
Operational
Does the proposed system solve problems or take advantage of opportunities?
Scheduling
Can the project time frame and completion dates meet organizational deadlines?
Legal and Contractual
What are the legal and contractual ramifications of the proposed system development project?
Political
How do key stakeholders view the proposed system?
what are the four general rules of technical risk assessments
Four general rules emerged as technical risk assessments:
Larger projects are riskier than smaller projects.
A system in which the requirements are easily obtained and highly structured will be less risky than one in which requirements are messy, ill structured, ill defined, or subject to the judgment of an individual.
The development of a system employing commonly used or standard technology will be less risky than one employing novel or nonstandard technology.
A project is less risky when the user group is familiar with the systems development process and application area than if unfamiliar.
what are project risk factors
Project Risk Factors
Project size
Team size, organizational departments, project duration, programming effort
Project structure
New vs. renovated system, resulting organizational changes, management commitment, user perceptions
Development group
Familiarity with platform, software, development method, application area, development of similar systems
User group
Familiarity with IS development process, application area, use of similar systems
what are project risk factors
Project size
Team size, organizational departments, project duration, programming effort
Project structure
New vs. renovated system, resulting organizational changes, management commitment, user perceptions
Development group
Familiarity with platform, software, development method, application area, development of similar systems
User group
Familiarity with IS development process, application area, use of similar systems
what are the consequences of not assessing and managing risks
The potential consequences of not assessing and managing risks can include:
Failure to attain expected benefits from the project
Inaccurate project cost estimates.
Inaccurate project duration estimates.
Failure to achieve adequate system performance levels.
Failure to adequately integrate the new system with existing hardware, software, or organizational procedures.
what is technical feasibility
Technical feasibility: a process of assessing the development organization’s ability to construct a proposed system
what are the characteristics of a good systems analyst
Good Systems Analyst Characteristics:
Impertinence—question everything
Impartiality—consider all issues to find the best organizational solution
Relax constraints—assume anything is possible
Attention to details—every fact must fit
Reframing—challenge yourself to new ways
Deliverables for Requirements Determination:
From interviews and observations
interview transcripts, observation notes, meeting minutes
From existing written documents
mission and strategy statements, business forms, procedure manuals, job descriptions, training manuals, system documentation, flowcharts
From computerized sources
Joint Application Design session results, CASE repositories, reports from existing systems, displays and reports from system prototype
methods for determining requirements
Interviewing individuals
Interviewing groups
Observing workers
Studying business documents
interview and listening
One of the primary ways analysts gather information about an information systems project
An interview guide is a document for developing, planning and conducting an interview.
Define NGT
A facilitated process that supports idea generation by groups
Process
Members come together as a group, but initially work separately.
Each person writes ideas.
Facilitator reads ideas out loud, and they are written on a blackboard or flipchart.
Group openly discusses the ideas for clarification.
Ideas are prioritized, combined, selected, reduced.
Used to complement group meetings or as part of JAD effort
what is direct observation
Direct Observation
Watching users do their jobs
Used to obtain more firsthand and objective measures of employee interaction with information systems
Can cause people to change their normal operating behavior
Time-consuming and limited time to observe
define document analysis
Document Analysis
Review of existing business documents
Can give a historical and “formal” view of system requirements
What types of info is to be discovered during document analysis
Types of information to be discovered: Problems with existing system Opportunity to meet new need Organizational direction Names of key individuals Values of organization Special information processing circumstances Reasons for current system design Rules for processing data
what is a written work procedure
Useful document: Written work procedure
For an individual or work group
Describes how a particular job or task is performed
Includes data and information used and created in the process
what are potential problems with procedure documents
Potential Problems with Procedure Documents:
May involve duplication of effort
May have missing procedures
May be out of date
May contradict information obtained through interviews
define formal systems
Formal Systems: the official way a system works as described in organizational documentation (i.e. work procedure)
Define informal systems
Informal Systems: the way a system actually works (i.e. interviews, observations)
what is a business form
Useful document: Business form
Used for all types of business functions
Explicitly indicates what data flow in and out of a system and data necessary for the system to function
Gives crucial information about the nature of the organization
why sample completed rather than blank
Can determine type of data going into each blank
Can determine size of data going into each blank
Can determine which blanks are not used or not always used
Can see data relationships
what is the report document in analysis of the system
Useful document: Report
Primary output of current system
Enables you to work backwards from the report to the data needed to generate it
Useful document: Description of current information system
define JAD
Joint Application Design (JAD)
Brings together key users, managers, and systems analysts
Purpose: collect system requirements simultaneously from key people
Conducted off-site
Define group support systems
Group Support Systems
Facilitate sharing of ideas and voicing of opinions about system requirements
what are the contemporary methods for determining system requirments
CASE tools
Used to analyze existing systems
Help discover requirements to meet changing business conditions
System prototypes
Iterative development process
Rudimentary working version of system is built
Refine understanding of system requirements in concrete terms
case tools during JAD
Upper CASE tools are used
Enables analysts to enter system models directly into CASE during the JAD session
Screen designs and prototyping can be done during JAD and shown to users
define JAD
Intensive group-oriented requirements determination technique
Team members meet in isolation for an extended period of time
Highly focused
Resource intensive
Started by IBM in 1970s
using a prototype during system requirements
Quickly converts requirements to working version of system
Once the user sees requirements converted to system, will ask for modifications or will generate additional requests
when is using prototyping during requirements determination
Most useful when:
User requests are not clear.
Few users are involved in the system.
Designs are complex and require concrete form.
There is a history of communication problems between analysts and users.
Tools are readily available to build prototype.
drawbacks to using prototypes during requirements determination
Drawbacks
Tendency to avoid formal documentation
Difficult to adapt to more general user audience
Sharing data with other systems is often not considered
Systems Development Life Cycle (SDLC) checks are often bypassed
Define BPR
Business Process Reengineering (BPR): search for and implementation of radical change in business processes to achieve breakthrough improvements in products and services
goals for determining system requirements using radical methods
Goals Reorganize complete flow of data in major sections of an organization. Eliminate unnecessary steps. Combine steps. Become more responsive to future change
what are key business processes
Key business processes
Structured, measured set of activities designed to produce specific output for a particular customer or market
Focused on customers and outcome
Same techniques as requirements determination are used
what are disruptive technologies
Information technologies must be applied to radically improve business processes.
Disruptive technologies are technologies that enable the breaking of long-held business rules that inhibit organizations from making radical business changes
requirements determination using agile methods
Continual user involvement Replace traditional SDLC waterfall with iterative analyze–design–code–test cycle Agile usage-centered design Focuses on user goals, roles, and tasks The Planning Game Based on eXtreme programming Exploration, steering, commitment
Agile Usage-Centered Design Steps
Gather group of programmers, analysts, users, testers, facilitator.
Document complaints of current system.
Determine important user roles.
Determine, prioritize, and describe tasks for each user role.
Group similar tasks into interaction contexts.
Associate each interaction context with a user interface for the system, and prototype the interaction context.
Step through and modify the prototype
ecommerce to determine system requirements
Determining system requirements for Pine Valley furniture’s WebStore
System layout and navigation characteristics
WebStore and site management system capabilities
Customer and inventory information
System prototype evolution
