SYSTEM ANALYSIS AND DESIGN

Chapter 1

Systems Analysis and Design is the process people use to create (automated) information systems.

*What is an Information System?

An information system is an arrangement of people, data, processes, interfaces, networks, and technology that interact for the purpose of supporting and improving both day-to-day operations in a business (sometimes called data processing), as well as supporting the problem solving and decision making needs of management (sometimes called information services).

Information system analysis and design is the complex organizational process whereby computer-based information systems are developed and maintained.

Organizations can respond to and anticipate problems and opportunities through innovative uses of information technology. Information system analysis and design is, therefore, an organizational improvement process. Analysis and design of IS is based on your understanding of the organization's objectives, structure, and processes as well as your knowledge of how to exploit information technology for advantage.

*What is a Computer Application System?

A computer application is computer-based solution to one or more business problems and needs. One or more computer applications are typically contained within an information system. Application software is software designed to support a specific organizational function or process, such as inventory management, payroll, or market analysis.

Overall Information system includes:

• Application Software
• Hardware and system (OS /middleware ) software
• Documentation and triaging materials
• Job roles associated with the system
• Controls to prevent theft or fraud
• The people who use the software to perform their jobs.

Components of Information system

1. Data

Raw facts about people objects and events in an organization .E.g. customer account number, customer balance. Information is the data that have been processed and presented in a form suitable for human interpretation, often with the purpose of revealing trends or patterns.

2. Data flow

Data in motion, moving from one place in a system to another.

3. Processing Logic

The steps by which data are transformed or moved and a description of the events that trigger these steps.

Types of Information system

1. Transaction processing system
2. Management Information system
3. Decision support system
4. Expert system
5. Office automation system
6. Executive Information system
7. Knowledge work system

Transaction processing system

A TPS collects and stores information about transactions, and controls some aspects of transactions. A transaction is an event of interest to the organization. E.g. a sale at a store.

A TPS is a basic business system. It:

• serves the most elementary day-to-day activities of an organization;
• supports the operational level of the business;
• Supplies data for higher-level management decisions.
• is often critical to survival of the organization
• mostly for predefined, structured tasks
• can have strategic consequences (e.g. airline reservation system)
• usually has high volumes of input and output
• provides data which is summarized into information by systems used by higher levels of management
• Need to be fault-tolerant.

On-line transaction processing: A transaction processing mode in which transactions entered on-line are immediately processed by the CPU.

Sub-species of TPS:

a) Manufacturing and production systems: Systems that supply data to operate monitor and control the production process. E.g. purchasing, receiving, shipping, process control, robotics, inventory systems, scheduling, engineering, operations, quality control, resource management etc.

E.g. A system in a factory that:

• gets information from measuring samples of products
• does statistical analysis of samples
• shows when operators should take corrective action

b) Sales and Marketing systems: Systems that support the sales and marketing function by facilitating the movement of goods and services from producers to customers.

Examples:

• sales support - keep customer records, follow-up
• telemarketing - use phone for selling
• order processing - process orders, produce invoices, supply data for sales analysis and inventory control
• point-of-sale - capture sales data at cash register often by scanner
• Customer credit authorization - advice on credit to be allowed to customer.
• Example:
  A Store's Sales System would:
• automatically record and total purchase transactions and prints out a packing list
• improve customer service
• maintain customer data

C)  Finance & Accounting Systems: Systems that maintain records concerning the flow of funds in the firm and produce financial statements, such as balance sheets and income statements. E.g. for Budgeting; General Ledger; Billing: Cost Accounting, Accounts Receivable / Payable; Funds Management Systems, Payroll. They were among the earliest systems to be computerized.

Examples of financial systems: cash management, loan management, check processing, securities trading.
Example: Visa's Credit Card payment system.

d) Human Resources System: Systems that deal with recruitment, placement, performance evaluation, compensation, and career development of the firm's employees.

Examples: personnel record keeping, applicant tracking, positions, training and skills, benefits.

Management Information system

It takes the relatively raw data available through a TPS and converts them into a meaningful aggregated form that managers need to conduct their responsibilities; monitoring performance and managing an organization .Transactions recorded in a TPS are analyzed and reported by an MIS.

They have large quantities of input data and they produce summary reports as output. Used by middle managers. An example is an annual budgeting system.

Decision Support system (DSS)

 DSS helps strategic management staff (often senior managers) make decisions by providing information, models, or analysis tools.  Instead of providing summaries of data, as with an MIS, a DSS provides an interactive environment in which decision makers can quickly manipulate data and models of business operations. It supports semi structured and unstructured decisions (structured decisions can be automated). It is used for analytical work, rather than general office support.

They are flexible, adaptable and quick.  They support the decision process and often are sophisticated modeling tools so managers can make simulations and predictions. A DSS is composed of a database (which may be extracted from a TPS or MIS), mathematical or graphical models of business processes, and a user interface that provides a way for the decision makers, usually a non-technical manager, to communicate with the DSS.

Their inputs are aggregate data, and they produce projections. An example job for a DSS would be a 5 year operating plan.

Expert Systems

It attempts to codify and manipulate knowledge rather than information. If-then-else rules or other knowledge representation forms describe the way an expert would approach situations in a specific domain of problems.

Knowledge engineers perform knowledge acquisition; they are similar to systems analysis but are trained to use different techniques, as determining knowledge is considered more difficult than determining data.

Office automation system (OAS) 

OAS provides individual's effective ways to process personal and organizational data, perform calculations, and create documents.
E.g. word processing, spreadsheets, file managers, personal calendars, presentation packages
for are used for increasing personal productivity. They reduce "paper warfare". OAS software tools are often integrated (e.g. Word processor can import a graph from a spreadsheet) and designed for easy operation.

OAS Subspecies:

Communication systems: helps people work together by sharing information in many different forms
Teleconferencing (including audio conferencing, computer conferencing, videoconferencing), electronic mail, voice mail, fax

Groupware system: helps teams work together by providing access to team data, structuring communication, and making it easier to schedule meetings. For sharing information, controlling work flows, communication/integration of work

Executive information system (EIS):

Also known as an Executive Support System (ESS), it provides executives information in a readily accessible, interactive format. They are an MIS for executive use. An EIS/ESS usually allows summary over the entire organization and also allows drilling down to specific levels of detail.

Used by top level (strategic) management. They are designed to the individual. They let the CEO of an organization tie in to all levels of the organization. They are very expensive to run and require extensive staff support to operate.

KNOWLEDGE WORK SYSTEMS (KWS): are used by technical staff. KWS use modeling functions to convert design specifications into graphical designs. They may include computer-aided design/manufacture (CAD/CAM).

System and Information Systems

 Information system share common characteristics with all systems. These characteristics are important if you are going to model a specific system sufficiently to convey key attributes to clients.

It leads to questions why do we model a system and how?

n  Exercise: What details would you give to describe the universe?  The galaxy?  The solar system?  The Earth’s ecosystem? Is the Earth’s ecosystem part of the Universe? Would you include details in the ecosystem when talking about the universe? 

System Def.

A SYSTEM is a set of:

w   interrelated components

w   working together

w   for a common purpose

A system can be described as having nine characteristics

w  Components

w  Interrelations (of Components)

w  Boundary

w  Purpose

w  Environment

w  Interfaces

w  Constraints

w  Input

w  Output

1) Components

n  Irreducible part

w  Or

n  Aggregation of parts that make a single “object” (e.g., a modem is a single object that is actually made of lots of circuits and switches, etc.)

n  Aggregations are called “subsystems”

2) Interrelations (of Components)

n  Function of one component ties it to the function of others within the system

n  System is working toward some purpose

3) Boundary

n  what separates the system from its environment

n  the system lies within the boundary

4) Purpose

n  Overall goal or function of the system

n  In structured systems design, one rule is any system you cannot describe in a single phrase is actually more than one function

n  But complex system has lots of subsystems with their own functions

n  E.g. human system is to “live” but w/ sub systems to breed (reproductive system), eat (digestive system), etc.

5) Environment

n  Made up of components as well

n  Are components important? Yes

n  Are components under our control? No

n  Note that we do influence environment with outputs.  But do not control

n  Examples: political, social, economical, ecological

6) Interfaces

n  Points at which the system meets its environment

n  Also exist between subsystems

n  In computer systems external interfaces are “Public” and internal are “Private”

n  Private interfaces can either be for privacy or to eliminate extraneous information (and reduce potential mistakes or info overload.

7) Constraints

n  Limitations

n  Can be internal (e.g., resources)

n  Can be external (e.g., rules and realities)

n  Constraints are limits to what a system can do as a result of external rules and realities or internal decisions

8) Input

n  A system takes input from its environment in order to function

n  Starts the cascade of the system

9) Output

n  Output is what a system returns to its environment as a result of achieving its purpose

n  In information systems, you have inputs, processing, and outputs of data

n  Process is the function of the (sub)system

n  Inputs are what data it takes in

n  Outputs are the data or information result of the processing

n  Example, fdouble(x) = x*2 is function. 

n  If input is 5, output is 10.

The Systems Analyst - A Key Resource

Many organizations consider information systems and computer applications as essential to their ability to compete or gain competitive advantage. Information has become a management resource equal in importance to property, facilities, employees, and capital.

All workers need to participate in the development of these systems and applications – not just the computer and information specialists.  But one specialist plays a special role in systems and applications development, the systems analyst.

*A systems analyst(s) facilitates the development of information systems and computer applications. The systems analyst performs systems analysis and design.

*Systems analysis      is the study of a business problem domain for the purpose of recommending improvements and specifying the business requirements for the solution.

*Systems design         is the specification or construction of a technical, computer-based solution for the business requirements identified in a systems analysis. (Note:  Increasingly, the design takes the form of a working prototype.).

The Systems Analyst as a Modern Business Problem Solver

*Why do businesses need Systems Analysts?

The system analyst bridges the communications gap between those who need the computer and those who understand the technology.

*What is a Systems Analyst?

Systems analysts are people who understand both business and computing. Systems analysts study business problems and opportunities and then transform business and information requirements of the business into the computer-based information systems and computer applications that are implemented by various technical specialists including computer programmers

A formal definition:

A systems analyst facilitates the study of the problems and needs of a business to determine how the business system and information technology can best solve the problem and accomplish improvements for the business. The product of this activity may be improved business processes, improved information systems, or new or improved computer applications frequently all three.

When information technology is used, the systems analyst is responsible for:

Ø  the efficient capture of data from its business source

Ø  the flow of that data to the computer

Ø  the processing and storage of that data by the computer

Ø  the flow of useful and timely information back to the business and its people

*Information technology is a contemporary term that describes the combination of computer technology (hardware and software) with telecommunications technology (data, image, and voice networks).

*What is a Systems Analyst?

A systems analyst is a business problem solver.

A systems analyst helps the business by solving its problems using system concepts and information technology. A systems analyst sell business management and computer users the services of information technology. A systems analyst sells change .The role of systems analyst is changing into two distinct positions or roles, business analyst and application analyst.

*A business analyst is a systems analyst that specializes in business problem analysis and technology-independent requirements analysis.

*An application analyst is a systems analyst that specializes in application design and technology-dependent aspects of development. A synonym is system or application architect.

*What Does A System Analyst Do?

*A system analyst is a system-oriented problem solver.

*System problem solving is the act of studying a problem environment in order to implement corrective solutions that take the form of new or improved systems.

*Most systems analysts use some variation of a system problem solving approach called a system development life cycle.

*A systems development life cycle (SDLC) is a systematic and orderly approach to solving system problems.

Analytical Skills for System Analysis

Four Sets of Analytical Skills

§  Systems Thinking

§  Organizational Knowledge

§  Problem Identification

§  Problem Analyzing and Solving

1. Systems Thinking

§  Most important skill for analysis is to be able to identify something as a system. The identification involves recognizing each of the system's characteristics. For e.g. Identifying the the component of system, where the boundary lies and all of the relevant inputs.

§  Once you have identified a system, what is the value of thinking of something as a system? Visualizing a set of things and their interrelationships a as a system allows you to translate a specific physical situations into more general, abstracts terms.

§  From abstraction you can think about essential characteristics of specific system.

§  Abstraction allows analyst to gain insights into specific system, to question assumptions, provide documentation and manipulate the system without disrupting the real situation documentation and manipulate without disrupting the real situation.

Applying systems thinking to information system

§  Information systems can be seen as subsystems in larger organizational systems. Taking input from, and returning output to, their organizational systems.

§  Different level of analysis can be done. One can understand only physical system that takes input, processes data, and returns output.

§  Another can analyze the logical system using logical description of an information system that focuses on the flow and transformation of data.

§  The physical system is one possible implementation of the more abstract, logical information system description.

§  Data flow diagrams represent information systems as systems. It represents Inputs, outputs, system boundaries, environment, subsystems, and interrelationships. Purpose and constraints are difficult to illustrate and must therefore be documented using other notations...

2. Organizational Knowledge

As a system analyst you should understand the working of organization. Also as system analyst whether you are in-house or contract custom software developer, you must be familiar with following:

§  Knowledge of specific functions and procedures of organization and department

§  How work officially gets done

§  Internal policies

§  Competitive and regulatory environment

§  Organizational strategies and tactics

3.  Problem Identification

 Problem is the difference between an existing situation and desired situation... Problem identification is process of defining differences. Differences are defined by comparing the current situation to the output of a model that predicts what the output should be. You must develop a repertoire of models to define the differences between what is and what ought to be. Every functional area of the organization will use different models to find problems; what is helpful in accounting will not necessarily works well in manufacturing.

Problem Analyzing and Solving 

Four Phases:

1. Intelligence

   All relevant information is collected

2. Design

Alternatives are formulated

3. Choice

Best alternative solution is chosen

4. Implementation

Solution is put into practice

4. Technical skills

Constant re-education is necessary as technology changes rapidly

§  Activities to keep skills up-to-date

o   Trade publications

o   Professional societies

o   Attend classes or teach at a local college

o   Attend courses sponsored by organization

o   Conferences and trade shows

o   Browse Websites

o   Participate in new groups and conferences

§  Understanding of a wide variety of technologies is required

o   Microcomputers, workstations, minicomputers and mainframe computers

o   Programming languages

o   Operating systems

o   Database and file management systems

o   Data communication standards

o   Systems development tools and environments

o   Web development languages and tools

o   Decision support system generators

5. Management Skill

 Management skill is needed to know how to manage your own work and how to use organizational resources in the most productive ways possible. Self-management is an important skill for an analyst.

Four categories:

1. Resource Management
2. Project Management
3. Risk Management
4. Change Management

Resource Management

o   Systems analyst needs to know how to get the most out of the resources of an organization, including team members

o   Includes the following capabilities

-   Predicting resource usage

-   Tracking resource consumption

-   Effective use of resources

-   Evaluation of resource quality

-   Securing resources from abusive use

-   Relinquishing resources when no longer needed

Project Management

o   Two Goals

-   Prevent projects from coming in late

-   Prevent projects from going over budget

o   Assists management in keeping track of project’s progress

o   Consists of several steps

-   Decomposing project into independent tasks

-   Determining relationships between tasks

-   Assigning resources and personnel to tasks

Risk Management

o   Ability to anticipate what might go wrong in a project

o   Minimize risk and/or minimize damage that might result

o   Placement of resources

o   Prioritization of activities to achieve greatest gain

Change Management

o   Ability to assist people in making transition to new system

o   Ability to deal with technical issues related to change

-   Obsolescence

-   Reusability

6. Interpersonal Skills

·         Mastery of interpersonal skills is paramount to success as a Systems Analyst

·         Four types of skills:

§  Communication skills

§  Working alone and with a team

§  Facilitating groups

§  Managing expectations

§  Communication Skills

o   Effective communication helps to establish and maintain good working relationships with clients and colleagues

o   Skills improve with experience

o   Three types used by Systems Analyst

§  Interviewing and Listening

§  Questionnaires

§  Written and Oral Presentations

·         Interviewing and Listening

o   Means to gather information about a project

o   Listening to answers is just as important as asking questions

o   Effective listening leads to understanding of problem and generates additional questions

·         Questionnaires

o   Advantages:

§  Less costly than interviews

§  Results are less biased due to standardization

o   Disadvantages

§  Less effective than interviews due to lack of follow-up

o   Written and Oral Presentations

§  Used to document progress of project and communicate this to others

§  Communication takes several forms:

o   Meeting agenda

o   Meeting minutes

o   Interview summaries

o   Project schedules and descriptions

o   Memoranda requesting information

o   Requests for proposals from vendors and contractors

o   Oral presentations

§  Steps to Improving Communication Skills

§  Practice

·         Conduct a training class

·         Volunteer to speak

§  Videotape presentation and do a self-appraisal of your skills

§  Make use of college writing centers

§  Take classes on business and technical writing

·         Working Alone and with a Team

§  Working alone on aspects of project involves managing:

o   Time

o   Commitments

o   Deadlines

§  Team work involves establishing standards of cooperation and coordination

§  Facilitating Groups

§  Involves guiding a group without being a part of the group

§  Useful skill for sessions such as Joint Application Development (JAD)

§  Managing Expectations

§  Managing expectations is directly related to successful system implementation

§  Skills for successful expectation management

o   Understanding of technology and workflows

o   Ability to communicate a realistic picture of new system to users

o   Effective education of management and users throughout systems development life cycle