Introduction

Introduction System Analysis and DesignCourse Objectives

To provide you with new ways of looking at information in the world in order to solve business problemsTo introduce you to concepts and methods of SADTo describe the systems development life cycle (SDLC)To teach you effective methods for gathering essential information during system analysisTo teach you approaches to documenting and modeling of gathered informationTo teach you effective methods for designing systems to solve problems effectively using technology

Topics coveredSystems conceptThe system development environment Types of information systems Rapid application development Role of the systems analyst Managing an IT project Initiating and planning a systems development project Determining systems requirements Process modeling Logic modeling Project documentation Understanding the elements of systems design Designing the user interface Designing system interfaces, controls and security

3Lecture PlanLecture 1Introduction to System Analysis and DesignLecture 2Roles & Need of System AnalystLecture 3System Development CycleLecture 4System Development CycleLecture 5System documentation ConsiderationLecture 6System documentation ConsiderationLecture 7System PlanningLecture 8System PlanningLecture 9System PlanningContd..Lecture 10Modular and Structured Design Lecture 11Modular and Structured DesignLecture 12Modular and Structured DesignLecture 13System Design and ModelingLecture 14System Design and ModelingLecture 15System Design and ModelingLecture 16Input and OutputLecture 17Input and OutputLecture 18Input and OutputContdLecture 19System Implementation & MaintenanceLecture 20System Implementation & MaintenanceLecture 21System Implementation & MaintenanceLecture 22OO Analysis / DesignLecture 23OO Analysis / DesignLecture 24OO Analysis / DesignCourse ContentsIntroduction (1 Lecture)System Definition and concepts, System Environments and Boundaries. Real-time and distributed systems, Basic principles of successful systems, Structured System Analysis and DesignSystems Analyst (1 Lecture)Roles and Need of Systems Analyst. Qualifications andresponsibilities. System Analysis as a ProfessionSystem Development Cycle(2 Lecture)Introduction to Systems Development Life Cycle (SDlC). Various phases of SDlC: Study, Analysis, Design, Development, Implementation, MaintenanceSystems documentation consideration(2 Lectures)Principles of Systems Documentation, Types of documentation and their importance, Enforcing documentation discipline in an organizationSystem Planning(3 Lectures)Data and fact gathering techniques : Interviews, Group Communication Questionnaires, Presentations & Site Visits. Assessing Project Feasibility: Technical, Operational, Economic, Cost Benefits Analysis, Schedule, legal and contractual, Political. Modular and Structured Design(3 Lectures)Module specifications. Top-down and bottom-up design. Module coupling and cohesion. Structure ChartsSystem Design and Modeling(3 lectures)Process Modeling, logical and physical design, Conceptual Data Modeling: Entity Relationship Analysis, Entity-Relationship Modeling, DFDs, Concepts of Normalization. ,Process specification tools, Decision Tree, Decision Tables. Documentation: Data Dictionary, Recording Data Descriptions13Input and Output(3 Lectures)Classification of forms, Input/output forms design. User-interface design, Graphical interfaces. Standards and guidelines for GUI design.System Implementation and Maintenance(3 Lectures)Planning considerations. Conversion methods, procedures and controls. System acceptance criteria. System Evaluation and Performance. Testing and Validation. Preparing User Manual. Maintenance Activities and IssuesOO Analysis / Design(3 Lectures)Introduction to UML OO Development Life Cycle and Modeling. Static and dynamic modeling. Comparison of OO and Module-oriented Approach. Modeling using UML.

(Object Oriented Analysis and Design is approach that models a system as a group of interacting objects. Each objects represent some entity of interest in the system being modeled by its class, its state (data elements) and its behavior.)16System Analysis and Design (SAD)SystemA SYSTEM is a set of: interrelated components working together for a common purpose

System AnalysisUnderstanding and specifying in detail what an information system should doSystem DesignSpecifying in detail how the parts of an information system should be implemented

An ideaAnalysis

Design andImplementationCompletedInformationSystemSYSTEMS ANALYSIS AND DESIGN: A Condensed (Informal) PerspectiveTime21 Systems Analysis and Design is the process, people use to create (automated) information systems

SystemsAnalysis& DesignInformationSystem22

SYSTEMS ANALYSIS AND DESIGN: A Complete (Formal) PerspectiveSystems PlanningSystems AnalysisSystems DesignSystems ImplementationSystems EvolutionPlanningEvolutionImplementationDesignAnalysis23System PlanningA methodical approach to the formulation of plans and programs for safe, efficient, and balanced Information System.

The process includes the setting of goals and objectives; the collection of data of existing conditions; the simulation of future activities; the formulation of alternative planned changes; the evaluation of the changes against the desired goals and objectives and the decisions about recommendations that are feasible, desirable, and appropriate.

System AnalysisSystem development can generally be thought of having two major components: systems analysis and systems design.

In System Analysis more emphasis is given to understanding the details of an existing system or a proposed one and then deciding whether the proposed system is desirable or not and whether the existing system needs improvements.

Thus, system analysis is the process of investigating a system, identifying problems, and using the information to recommend improvements to the system. System analysis is a combined process dissecting the system responsibilities that are based on the problem domain characteristics and users requirements.

System DesignSystems design is the process of defining the architecture (structure+behavior), components, modules, interfaces, and data for a system to satisfy specified requirements.

Logical design: The logical design of a system pertains to an abstract representation of the data flows, inputs and outputs of the system. This is often conducted via modelling.

Physical Design: The physical design relates to the actual input and output processes of the system. This is laid down in terms of how data is input into a system, how it is verified/authenticated, how it is processed, and how it is displayed as output.

Alternative Design Methodologies

Rapid application development (RAD): Rapid application development (RAD) is a methodology in which a systems designer produces prototypes for an end-user. The end-user reviews the prototype, and offers feedback on its suitability. This process is repeated until the end-user is satisfied with the final system.

Joint application design (JAD): Joint application design (JAD) is a methodology which evolved from RAD, in which a systems designer consults with a group consisting of the following parties:Executive sponsorSystems DesignerManagers of the systemJAD involves a number of stages, in which the group collectively develops an agreed pattern for the design and implementation of the system.

System ImplementationA collection of interdependent physical devices together with their programming which provides the functionality and performance for which the system was designed.

System Implementation is the phase in the Software Development lifecycle, during which: The hardware and software system components are installed;The selected software is configured and tested;The software may be customised to meet local functional requirements; data mapping, cleansing and migration take place; reporting requirements are specified and reports produced;the whole system is tested before being approved, signed off and becoming a fully operational production system.

System EvolutionSystem Evolution is concerned with the processes of evolving an existing system to meet new requirements.

The Evolution Problem: In order that systems remain useful, they must evolve to reflect changing requirements and changes to the organization in which these systems are installed

System maintenance is increasingly expensive and maintaining existing systems consumes an increasing proportion of an organisations budget

29What is Information SystemAn Information System (IS) is a collection of interrelated components that collect, process, store, and provide as output the information needed to complete a business task.

A payroll system, for example, collects information on employees and their work, processes and stores that information, and than produces paychecks and payroll reports for the organization. Then information is provided to manufacturing so the department can schedule production.

Contd..There are two approaches to ISs design:

Process-oriented: The process-oriented approach is based on what the system is supposed to do. The focus is on output and processing logic.

Data-oriented: The data-oriented approach is a strategy that focuses on the ideal organization of data, independent of where and how data are used within the system. This approach uses data model that describes the kinds of data needed in the system and the business relationships among the data (i.e. business rules).

Types of Information SystemsThe information systems found in most businesses include transaction processing systems, management information systems, executive information systems, decision support systems, expert systems, communication support systems, and office support systems.

FIGURE : Types of Information systemsTransaction processing systems (TPS)Transaction processing systems (TPS) capture and record information about the transactions that affect the organization. A transaction occurs each time a sale is made, supplies are ordered, an interest payment is made. Systems capable of transaction processing must pass tests for atomicity, consistency, isolation and durability, otherwise known as the ACID test.Transactions are known asatomic, meaning that the transaction will either happen or not. If one account is debited, then another account has to be credited.The transaction processing system must always beconsistentwith its own rules. If errors occur in the transaction on either side, then the transaction will fail.ContdIsolatingtransactions means that other processes never see information during the transaction. They may see information before or after the transaction, but not during the transaction. For example, if two people are booking the last theatre seat at the same time, they can both see the seat before the booking, but only one person will succeed in booking that seat.Transactions must bedurable. This means that when that final seat in the theatre has been booked and you have received notification that the seat is yours, it is permanently recorded. No matter what problems occur to the system, there are back-ups in place in the transaction processing system to ensure that the record stays permanent.Airline Reservation Systems

Management information systems (MIS)Management information systems (MIS) are systems that take information captured by TPS and produce reports that management needs for planning and controlling the business. MIS are possible because the information has been captured by the TPS and placed in organizational databases.

Financial Accounting System, Library Information SystemExecutive information systems (EIS)Executive information systems (EIS) provide information for executives to use in strategic planning. Some of the information comes from the organizational databases, but much of the information comes from external sources news about competitors, stock market reports, economic forecasts, and so on.

Cambridge Systematics has ESS to support the investment planning process for the Ministry of Transportation.Decision support systems (DSS)Decision support systems (DSS) allow a user to explore the impact of available options or decisions. Whereas an MIS produce reports, DSS provide an interactive environment in which decision makers can quickly manipulate data and models of business operations. A DSS has three parts. The first part is composed of a database (which may be extracted from TPS or MIS). The second part consists of mathematical or graphical models of business processes. The third part is made up of a user interface (or dialogue module) that provides a way for the decision makers to communicate with the DSS. An EIS is a DSS that allows senior management to explore data starting at a high level of aggregation and selectively drill down into specific areas where more detailed information and analysis are required. Geographic Information System (GIS)

Expert systems (ES)Expert systems (ES) replicate the decision-making process rather than manipulating information. If-then-else rules or other knowledge representation forms describe the way a real expert would approach situations in a specific domain of problems. Typically, users communicate with an ES through an interactive dialogue. The ES asks questions (which an expert would ask) and the end user supplies the answers. Those answers are then used to determine which rules apply, and the ES provides a recommendation based on the rules.some successful expert systems are:DENDRAL SYSTEM, MYCIN, CRYSALIS

Communication support systems (CSS)Communication support systems (CSS) allow employees to communicate with each other and with customers and suppliers. Communication support now includes e-mail, fax, Internet access, and video conferencing.Telme: A Personalized, Context-Aware Communication Support SystemTelesfor Telemedical Real-Time Communication Support System

Office support systems (OSS)Office support systems (OSS) help employees create and share documents, including reports, proposals, and memos. OSS also help to maintain information about work schedule and meetings.Office-by-Example (OBE) is an integrated office information systemMS Office Systems AnalystSystems Analyst is a business professional who uses analysis and design techniques to solve business problems using information technology and who develops ISs.Developing ISs is not just about writing programs. ISs are developed to solve problems for organizations, and systems analyst is often thought of as a problem solver rather than a programmer (see Figure on next slide ).

FIGURE : The analysts approach to problem solving.Roles of System AnalystThe system analyst is the person (or persons) who guides through the development of an information system. In performing these tasks the analyst must always match the information system objectives with the goals of the organization.Role of System Analyst differs from organization to organization. Most common responsibilities of System Analyst are following:System AnalysisSystem Analysis and DesignSystem Analysis, Design and Programming System AnalysisIt includes system's study in order to get facts about business activity.

It is about getting information and determining requirements.

This responsibility includes only requirement determination, not the design of the system.System Analysis and DesignHere apart from the analysis work, System Analyst is also responsible for the designing of the new system/application.System Analysis, Design and ProgrammingHere Analyst is also required to perform as a programmer, where he actually writes the code to implement the design of the proposed application.Due to the various responsibilities that a system analyst requires to handle, he has to be multifaceted person with varied skills required at various stages of the life cycle. In addition to the technical know-how of the information system development a system analyst should also have the following knowledge.Business knowledgeInterpersonal skillsProblem solving skills

Contd..Business knowledge: As the analyst might have to develop any kind of a business system, he should be familiar with the general functioning of all kind of businesses.

Interpersonal skills: Such skills are required at various stages of development process for interacting with the users and extracting the requirements out of them

Problem solving skills: A system analyst should have enough problem solving skills for defining the alternate solutions to the system and also for the problems occurring at the various stages of the development process.

Minimum Qualification for System AnalystMinimum Qualifications:Associate's degree in Computer Science or related field AND three years of systems/programming experience; OR, Bachelor's degree in Computer Science or related field AND two years of systems/programming experience; OR, Four years of systems and/or programming experience; OR, Any equivalent combination of experience and/or education from which comparable knowledge, skills and abilities have been achieved.

Duties InvolvedExamples of Duties:Consults with users to define system requirements, identify programming and output needs, and verify preliminary design and output.Recommends technical and procedural design for new or revised applications including flow charts, system specifications, and programming guidelines.Analyzes current and new programming languages, documentation, hardware, and software to identify possible applications and/or feasibility of applications for computer systems.Modifies and/or writes program code and/or job control language as needed.Writes documentation of system procedures and guidelines for systems users, as well as programs and program modifications.Contd..Confers with other data processing personnel in resolving problems involving program intent, input/output requirements, and other procedural and technical matters.Answers questions and provides technical assistance and/or training to system users.Reviews, evaluates, and documents existing programs and/or systems to identify and recommend the means of typing together interacting systems extending across university and/or functional lines.Reviews and analyzes system problems including system documentation and production output to identify solutions and/or make appropriate referrals.

System Analyst As a ProfessionIt's not what you're called, it's what you do.

Job titles and descriptions for analysts vary widely between organizations and the professional analysts may have titles as diverse as: Business Analyst, Systems Analyst, Business Systems Analyst, IT Specialist, Requirements Analyst, Consultant, Programmer/Analyst, etc.

Contd..The Modern Analyst must possesa variety of skillsincluding:Communication and interviewing skillsUnderstanding of the business model and processesProblem solving and structured analysis skillsPresentation and facilitation skillsProject management skillsSystems analysis and design methodologiesTechnical skillsIn smaller projects and small organizations the analyst may perform all of the above roles and may need to possess all of the above skills. In reality the roles performed by an individual analyst and the needed competencies vary from project to project and among various organizations.

Why SAD is ImportantSuccess of information systems depends on good System Analysis and DesignWidely used in industry - proven techniquesPart of career growth in IT - lots of interesting and well-paying jobs! Increasing demand for systems analysis skills

Text and Reference books1) J. Hoffer, Modern Systems Analysis and Design, Second Edition, Joey George and Joseph Valacich, Pearson Education.2) J. Whitten, L. Bentley and K. Dittman, Systems Analysis and Design Methods, Fifth Edition, Tata McGraw Hill.3) Dennis and B.H.Wixom, Systems Analysis and Design, First Edition, John Wiley and Sons, Inc.4) Roger S. Pressman, Software Engineering, Fifth Edition, Mcgraw Hill International Edition.