The Tools of Structured Analysis:

The Data Flow Diagram

The first step is to draw a data flow diagram (DFD). The DFD was-first developed by Larry Constantine as a way of expressing system requirements in a graphical form; this led to a modular design.

A DFD, also known as a "bubble chart,’’ has the purpose of clarifying system requirements and identifying major transformations that will be­ come programs in system design, So it is the starting point of the design phase that functionally decomposes the requirements specifications down to the lowest level of detail. 

A DFD consists of a series of bubbles joined by lines, The bubbles represent data transformations and the lines represent data flows in the system. The system takes orders from the customer (bookstore, library, etc.), checks them against an index (file) listing the books available, verifies. Customer credit through credit information files, and authorizes shipment with an invoice.

Data Dictionary

•A structured place to keep details of the contents of data flows, processes, and data store.

•It is a structured repository of data about data.

•It is a set of definitions of all DFD elements

Advantages of Data Dictionary

•Documentation- it is a valuable reference in any organization.

•It improves analyst/user communication by establishing consistent definitions of various elements, terms and procedures

•It is important step in building a database

Items to be defined in Data Dictionary

•Data Elements- smallest unit of data that provides for no further decomposition.

For example: date consists of day, month and year

•Data Structure- a group of data elements handled as a unit.

For example: phone is a data structure consisting of four data elements: area-code-exchange-number-extension.

•Data Flows and Data Stores- data flows are data structures in motion, whereas data stores are data structures at rest. A data store is a location where data structures are temporarily located.

Decision Tree

A decision tree is a decision support tool that uses a tree-like graph or model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility. It is one way to display an algorithm. Decision trees are commonly used in operations research, specifically in decision analysis, to help identify a strategy most likely to reach a goal. If in practice decisions have to be taken online with no recall under incomplete knowledge, a decision tree should be paralleled by a probability model as a best choice model or online selection model algorithm. Another use of decision trees is as a descriptive means for calculating conditional probabilities.

Structured English

Structured English borrows heavily from structured programming; it uses logical construction and imperative sentences designed to carry out instructions for action. Decisions are made through IF, THEN, ELSE, and so statements. The structured English for our publisher's discount policy is shown

COMPUTE-DISCOUNT

Add up the number of copies per book title

IF order is from bookstore
and-IF order is for 6 copies or more per book title
THEN: Discount is 25%
ELSE (order is for fewer than 6 copies per book title)
SO: no discount is allowed
ELSE (order is from libraries or individual customers)
order is for 50 copies or more per book title discount is 15%
ELSE IF order is for 20 to 49 copies per book title discount is 10%
ELSE IF order is for 6 to 19 copies per book title discount is 5%
ELSE SO:(order is for less' than 6 copies per book order) no discount is allowed
MEDIUM: 20 to 49 copies LARGE: 50 or more copies

From these examples we see that when logic is written out in English sentences using capitalization and multilevel indentation, it is structured English. In this tool, the logic of processes of the system is expressed by using the capitalized key words IF, THEN, ELSE, and so. Structures are indented to reflect the logical hierarchy. Sentences should also be clear, concise, and precise in wording and meaning.

Feasibility Study:

Feasibility Study

Many feasibility studies are disillusioning for both users and analysts. First, the study often presupposes that when the feasibility document is being prepared, the analyst is in a position to evaluate solutions. Second, most studies tend to overlook the confusion inherent in system development-the constraints and the assumed attitudes. If the feasibility study is to serve as a decision document, it must answer three key questions:

1. Is there a new and better way to do the job that will benefit the user?
2. What are the costs and savings of the alternative (S)?
3. What is recommended?

The most successful system projects are not necessarily the biggest or most visible in a business but rather those that truly meet user expectations. More projects fail because of inflated expectations than for any other reason.

Importance=Why Are Feasibility Studies so Important?

The information you gather and present in your feasibility study will help you:

 List in detail all the things you need to make the business work;

Identify logistical and other business-related problems and solutions;

Develop marketing strategies to convince a bank or investor that your business is worth considering as an investment; and Serve as a solid foundation for developing your business plan.

Economic Feasibility

Economic analysis is the most frequently used method for evaluating the effectiveness of a candidate system. More commonly known as cost/benefit analysis, the procedure is to determine the benefits and savings that are expected from a candidate system and compare them with costs. If benefits outweigh costs, then the decision is made to design and implement the system. Otherwise, further justification or alterations in the proposed system will have to be made if it is to have a chance of being approved. This is an ongoing effort that improves in accuracy at each phase of the system life cycle. More on cost/benefit analysis is covered in Chapter.

Technical Feasibility

Technical feasibility centers around the existing computer system (hardware, software , etc) and to what extent it can support the proposed addition. For example, if the current computer is operating at 80 percent capacity-an arbitrary ceiling-then running another application could overload the system or require additional hardware. This involves financial considerations to accommodate technical enhancements. If the budget is a serious constraint, then the project is judged not feasible.

In technical feasibility the following issues are taken into consideration.

       Whether the required technology is available or not

       Whether the required resources are available -

- Manpower- programmers, testers & debuggers

- Software and hardware

Once the technical feasibility is established, it is important to consider the monetary factors also. Since it might happen that developing a particular system may be technically possible but it may require huge investments and benefits may be less. For evaluating this, economic feasibility of the proposed system is carried out.

Behavioral Feasibility

People are inherently resistant to change, and computers have been known to facilitate change. An estimate should be made of how strong a reaction the user staff is likely to have toward the development of a computerized system. [t is common knowledge that computer installations have something to do with turnover, transfers, retraining, and changes in employee job status. Therefore, it is understandable that the introduction of a candidate system requires special effort to educate, sell, and train the staff on new ways of conducting business  In our safe deposit example, three employees are more than 50 years old and have been with the bank over 14 years, four years of which have been in safe deposit. The remaining two employees are in their early thirties. They joined safe deposit about two years before the study. Based on data gathered from extensive interviews, the younger employees want the programmable aspects of safe deposit (essentially billing) put on a computer. Two of the three older employees have voiced resistance to the idea. Their view is that billing is no problem. The main emphasis is customer service-personal contacts with customers. The decision in this case was to go ahead and pursue the project.

       Is the audience likely to adopt the behavior? Is the current behavior seen as a problem? How engrained or “rewarding” are the current or competing behaviors?

       How costly is it (time, effort, resources) for the audience segment to perform the behavior?

       How complex is the behavior (does it involve few or several elements)?

The System Development Life Cycle:

System Development Life Cycle (SDLC) Methodologies

SDLC (System Development Life Cycle), just as the name implies, is defined as the process (as a whole) of developing system or software to meet certain requirements. It covers many activities; starts from understanding why the system should be built, studying the project feasibility, analyzing problems, choosing the system design and architecture, implementing and testing it, up to delivering the system as product to the user. SDLC is a process of gradual refinement, meaning that it is done through several development phases. Each phase continues and refines what’s done in the previous phase. Commonly known development phases in SDLC are:

• Planning. It is the process of understanding why the system should be built and defining its requirements. It also includes feasibility study from several different perspectives, technical, economic, and organization feasibility aspects.
• Analysis. This phase includes activities such as problems identifying and analysis, and even predicting potential problems that may arise in the future regarding the system. The deliverables / products of this phase will drive how the system will be built and guide the developers’ works.
• Design. System analysis leads to design decision, which exactly determines how the system operates in terms of process, data, hardware, network infrastructures, user interface, and other important factors in the system environment.
• Implementation. This is probably the most resource-, cost-, and time-consuming phase of all. This is when the system is actually built, tested, and finally installed. It also includes activities such as user training and system maintenance. Some experts like to separate them into different phases Deployment and Maintenance. However the four phases are the most commonly known and accepted steps.

Recognition of Needs

One must know what the problem is before it can be solved. The basis of candidate system is recognition of need for improving the system. The key question is:

What is the problem?

This recognition of need leads to a preliminary survey or an initial investigation of current system to determine whether an alternative system can solve the problem. If the problem is serious enough, management may have an analyst look at it.

The idea for change may originate in the environment or within the firm. Environment-based ideas originate from customers, vendors, government sources etc. When investigated each of these ideas may lead to a problem definition. Idea for change may also come from with in the organization – top management, the user, the analyst. User-originated ideas also prompt initial investigation.

Impetus for System Change

The ideas for change originate in the environment or from within the firm Environment-based ideas originate from customers, vendors, government sources, and the like. For example, new unemployment compensation regulations may make it necessary to change the restructures. Customer complaints about the delivery of orders may prompt an investigation of the delivery schedule, the experience of truck drivers, or the volume of orders to be delivered. When investigated, each of these ideas may lead to a problem definition as a first step in the system life cycle process.

Feasibility Study

Depending on the results of the initial investigation, the survey is expanded to a more detailed feasibility study. As we shall learn, a feasibility study is a test of a system proposal according to its workability impact on the organization, ability to meet user needs, and effective use of resources. It focuses on there major questions:

• What are the user’s demonstrable needs and how does a candidate system meet them?
• What resources are available for given candidate systems? Is the problem worth solving?
• What are the likely impact of the candidate system on the organization? How will it fit within the organization’s master MIS plan?

Analysis

Analysis is a detailed study of the various operations performed by a system and their relationships with in and outside of the system. A key question is: -

What must be done to solve the problem?

During analysis, data are collected from the available files, decision points and transactions handled by the current system. Tools that are used in analysis are data flow diagrams, interviews, on-site observation, and questionnaires. The interview is a commonly used tool in analysis. Training, experience and common sense are required for collection of the information needed to do the analysis. Once the analysis is completed, the analyst understands that what is to be done?

Design
The tern design describes the final system and the process by which it is developed. It also refers to the technical blue print that will be applied in implementing the candidate system. It also includes the construction of programs and program testing. The key question is: -

How should the problem solved?

The first step in designing is to determine How the output is to be produced and in what format?

The second step is input data and master files (database) have to be designed to meet the requirements of the proposed output.
The third step includes a list of programs needed to meet the system’s objectives and complete documentation.

Finally, Details related to justification of the system and the impact of the candidate system on the user and the organization. These details are documented and evaluated by management.

Implementation

The implementation phase is directly concerned with user training, site preparation and file conversion. During the final testing, user acceptance testing is followed by the user training. Conversion usually takes place at about the same time when the user is being trained. Once the program become available and data are ready for testing and the results are OK then the program is run with “live” data. Otherwise, a diagnostic procedure is used to locate and correct errors in the program.

Post-Implementation and Maintenance

After the installation phase is completed and the user or staff is adjusted to the changes create by the candidate system. Evaluation and Maintenance begins. If the new information is inconsistent with the design specifications then changes have to be made. Hardware’s also require periodic maintenance to keep in tune with design specifications.

Changes in organizations requirements or environmental factors also call for system enhancements. This change requires evaluation, program modifications and further testing.

System Concepts and Information System Environment:

What is a SYSTEM?

•         A system is a group of interrelated components working together toward a common goal by accepting inputs and producing outputs in an organized transformation process.

–        Components and their attribution

•         Systems structure: relationship between components

•         Subsystems

–        Environment and Boundary

–        Input and Output

Definition of a System

          The term system may be defined as an orderly arrangement of a se t of interrelated and interdependent element that operate collectively to accomplish some common purpose or goal. For example – human body is a system, consisting of various parts such as head, heart, hands, legs and so on. The various body parts are related by mean of connecting networks of blood vessels and nerves and the system has a main goal of “living”. Thus, a system can be described by specifying its parts, the way in which they are related, and goals which they are expected to achieve. A business is also a system is also a system where economic resources such as people, money, material, machines, etc are transformed by various organizational processes (such as production, marketing, finance etc.) into goods and services. A computer based information system is also a system which is a collection of people, hardware, software, data and procedures that interact to provide timely information to authorized people who need it.

Type of system

1. Elements
2. interactive behavior
3. degree of human intervention
4. working/output

Characteristics of Systems

l      A component 

•         an irreducible part or aggregation of parts that make up a system, also called a subsystem

l      Interrelated components

•         Dependence of one subsystem on one or more subsystems

l      Boundary

•         The line that marks the inside and outside of a system and that sets off the system form its environment

l      Purpose

•         The overall goal or function of a system

l      Environment

•         Everything external to a system that interacts with the system

l      Interface

•         Point of contact where a system meets its environment or where subsystems meet each other.

l      Constraint

•         A limit to what a system can accomplish

l      Input

•         Whatever a system takes from its environment in order to fulfill its purpose

l      Output

•         Whatever a system returns  from its environment in order to fulfill its purpose

Open and Closed and closed system

l     Open system

A system that interacts freely with its environment, taking input and returning output

For example- The education system or any business process system will quickly change when the environment changes. To do this, an open system will interact with element that exist and influence from outside the boundary of the system.

l     Closed system

A system that is cut off from its environment and does not interact with it

For example- Consider a ‘throw-away’ type sealed digital watch, which is a system, composed of a number of components that work in a cooperative fashion designed to perform some specific task. This watch is a closed system as it is completely isolated from its environment for its operation. Such closed system will finally run down or become disorganized. This movement to disorder is termed on increase in entropy.

Formal & Informal Information Systems

 Formal Information System:
A formal information system is based on the organisation represented by the organization chart. The chart is a map of position and their authority relationship,indicated by boxes and connected by straight lines. it is concerned with the pattern of authority, communication and work flow.
Informal Information System:
The informal information system is employee based system design to meet personnel and vocational needs and to help in the solution of work-related problems. it also funnels information upward through indirect channels. In this way, it is considered to be a useful system because it works within the framework of the business and its stated policies.

Computer Based Information System (CBIS)

A CBIS is an organized integration of hardware and software technologies and human elements designed to produce timely, integrated, accurate and useful information for decision making purposes.

For any given application the following features must be present:-

Easy to use interactive (two way) interfaces

• Touch screen
• GUI
• Menu Driven Interface
• Color Screen
• Buttons
• Labels
• Voice Activated
• Tones, on phones

Use of advanced technologies

• Phone (inc WAP)
• digital television
• Teleconferencing (audio, video and computer)
• Integration of voice, data and images through ISDN’s (integrated services digital networks)
• Image transfer systems through facsimile

Fast processing

• Searching (Google gives you search times)
• Looking up name in a database

Rapid responses

• To input
• To requests

Management Information System

            Many experts have defined MIS in different language. A management information system has been defined by Davis and Olson as “an integrated user-machine system designed for providing information to support operational control, management control and decision making function is an organization”.           

Management

Information

Systems

Decision Support Systems – DSS (definition)

The best decision support systems provide high-level summaries and drilldowns to details.
Decision Support Systems (DSS) are a specific class of computerized information system that supports business and organizational decision-making activities. A properly designed DSS is an interactive software-based system intended to help decision makers compile useful information from raw data, documents, personal knowledge, and/or business models to identify and solve problems and make decisions.
Typical information that a decision support application might gather and present would be:

• Accessing all of your current information assets, including legacy and relational data sources, cubes, data warehouses, and data marts
• Comparative sales figures between one week and the next
• Projected revenue figures based on new product sales assumptions
• The consequences of different decision alternatives, given past experience in a context that is described

General Business Knowledge

 For an individual that’s new to business and wants to negotiate Procurement contracts at some point their career, one of the first things they need to do is start to build their knowledge and skills.

 To be a good negotiator you need knowledge and skills in a number of areas.

1. General business knowledge and skills.
2. Procurement knowledge and skills
3. Contracting knowledge and skills
4. Negotiation knowledge and skills 

Interpersonal Communicational System

 Interpersonal communication is usually defined by communication scholars in numerous ways, usually describing participants who are dependent upon one another. It can involve one on one conversations or individuals interacting with many people within a society. It helps us understand how and why people behave and communicate in different ways to construct and negotiate a social reality. While interpersonal communication can be defined as its own area of study, it also occurs within other contexts like groups and organizations. Interpersonal communication is the process that we use to communicate our ideas, thoughts, and feelings to another person. Our interpersonal communication skills are learned behaviors that can be improved through knowledge, practice, feedback, and reflection.