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Information Systems

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Information System (CS507)
LESSON 22
System Analysis
System analysis can be defined simply as: "The study of business problem domain to recommend
improvements and specify the business requirements for the solution."
Or alternatively as:
"A problem solving technique that decomposes a system into its component pieces for the purpose of
studying, how well those component parts work and interact to accomplish their purpose."
Both the definitions highlight following important points:
System analysis helps to create an understanding of the business processes, their linkage with
one another, the parameters governing the data flow within the business, the controls and
checks built into the processes and the reporting needs in a business where a problem exists
or for which the software needs to be designed.
System analysis creates the understanding and lays out the necessary relationships that will
assist in defining a solution to the problem or the design of the proposed software that will
meet the user needs.
These two points may be understood as providing a means for undertaking the following tasks:
A technique to map the system under study.
To drill down into the various aspects of the business process without losing sight of the complete
system.
To understand the Workability/Functionality of the subsystems and their role in achieving the
objectives of the system as well as controls and checks in place.
To establish the relationship or Level of interaction of each system with other components of the
system.
22.1 Computerized vs. Manual environment
Information systems are designed and developed for both types of environments. System analysis is done in
both situations covering business processes and flow of documents which include:
Documents being prepared to record transactions
Point of Origin of the data and documents
Who is responsible for originating
Destination/filing point/ultimate storage
Relationships between various divisions of the business in terms of data being received and
recorded from different transactions, financial and non-financial
Controls devised to ensure accuracy, integrity and reliability of data
Reports generated, frequency and distribution thereof to various users
The difference between the manual and computerized environment arises due to the following reasons,
quite simply because of the different nature of the environments:
Logical access control issues in computerized environment.
Duplication of clerical work generally observed in a manual environment is eliminated in
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Information System (CS507)
the computerized environment.
Automatic generation of specified reports: In a computerized environment as opposed to manual
data compilation.
Data integrity is more fully secured in a computerized environment with addition or authorized
changes in data being automatically updated for all purposes through a single button effort as
opposed to making changes or updating in each register or record affected by the same in a
manual environment.
Drill down function to conduct analysis of recorded data is available in a computerized environment
as opposed to undertaking a manual analysis of all data.
Flexibility of presenting data in desired or different format including using specified data to be
shown graphically is available in computerized environment.
Data Security and confidentiality can be assured to a higher degree in a computerized
environment.
22.2 Systems Analyst
"These are knowledge workers who facilitate the development of information systems and computer
applications by bridging the communications gap that exists between non-technical system users, and
System designers and developers."
Why do we need Systems Analysts?
Systems analysts work as a link between Business people, & Computer Programmers. Business People may
define the business to be computerized, i.e. establish scope of computerization. However, they may not
fully understand the capabilities and limitations of modern information technology.
Computer programmers apply information technology to build information systems which solves these
problems but need not fully understand the business usages they are computerizing or supporting.
Systems Analysts due to their expertise in development, knowledge of business processes, awareness of
industry best practices, bridge the gap by translating the scope of computerization into how the systems will
handle the transactional flows and the relationship between the various aspects of the business for the
programmers whilst keeping the overall objectives and requirements, both corporate and IT related in
perspective.
22.3 System Design
System Design maybe defined as "A problem solving technique that re-assembles a system's components
back into a complete system. This may involve adding, changing deleting pieces relative to the original
system" or alternatively as "the process or art of defining the hardware and software architecture,
components, modules, interfaces, and data for a computer system to satisfy specified requirements."
Once the existing system is analyzed and user requirements established they need to be either incorporated
into the existing computerized system or assist in the development of a new system.
The major components of system design are:
Designing usable and complete input
Designing well defined and usable output with flexibility to redefine presentation of outputs in
any form.
Designing file or database
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Information System (CS507)
Designing user interface (input screen as it would be seen by the user)
Designing usable and complete input
This includes the design of input forms to record data. The input forms should be accurate, easy to use,
consistent and simple. Preferably the input forms should not differ too greatly from the manual input forms
being used by a business, as this can help in the change management process. All Primary parameters
pertaining to the various input forms must be defined as part of the input design e.g. basic information
pertaining to various entities suppliers, customers, employees and chart of accounts. There are cases where
the definitions were incomplete resulting in an inability to produce a report on the basis of an undefined
parameter. Thus great care and diligence is required when undertaking this task.
Designing well defined output
Various considerations need to be kept in mind while defining parameters for desired output. These
should generally focus on:
Assuring purposeful output
Providing output as defined and required by users
Providing appropriate information
Assuring distribution of output as per client specified requirements.
Minimizing throughput time and Query time.
Ensuring that output is available in client required mode.
Many business managers due to lack of knowledge are not able to visualize their future reporting needs or
even define the end to end output requirements or linkages as they assume that these will be produced
magically by the computer. Unfortunately, the unexpressed wishes cannot be turned into reality unless
someone at the design and development stage had specified these needs and the same have been
accordingly parameterized. In situations where this is not done output designing becomes an open ended
process, which is neither time or cost beneficial for the organization.
Designing file or database
This serves following purposes:
Data accessibility is ensured to the user is ensured as and when required.
Data consistency ­ data updates in master file will automatically update the data in the whole
system.
Data is efficiently processed & stored.
Data integrity that is Correctness of data is ensured. This does not mean that incorrect
amounts entered into the computer will be automatically corrected by because the computer
only records what is entered but if there is an error in entering pre-defined parameters these
would be corrected or thrown up as an error. Further, the data processed according to the pre-
defined procedures every time around without any change unless an error has been caused to
the program handling the data.
22.4 Designing user interface
The design of what the user sees on the screen, that is, the interface, while entering data should be such that
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the user is familiar with. The information should be entered in a logical sequence e.g., if a user wants to add
an employee to the employee's master file, the information may be entered in the following sequence:
Employee ID, which can either be
Generated automatically by the system, or
Entered manually by the user
Name
Address
Contact information
Next of kin
Grade
Designation
Salary Details
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Information System (CS507)
LESSON 23
Benefits of Good System Design
Better understanding by the developer of the system. A properly designed system helps in
elaborating and understanding refined aspects of system.
System development becomes efficient. An error free designed system saves development time
since it helps in understanding without discussion.
A well designed system also helps in early detection of problems in critical areas, if any.
Better quality of reporting formats. Modifications can be made easily in the system.
Little maintenance is required in the operations phase.
23.1 System Analysis & Design Methods
Two approaches are followed for system analysis and design
Structured analysis and design ­ Which includes various tools, such as.
Flowcharting
Data Flow diagram
ERD
Object oriented analysis and design
23.2 Structured Analysis and Design
Structured analysis and design follows a set of good practices and generally accepted standards. Proper
documentation of the system is made by following standard rules.
23.3 Flow Chart
"A schematic representation of a sequence of operations as in a manufacturing process or computer
program."
Introduction
Flowchart is the most commonly used design and analysis technique. The diagrammatic presentation gives a
quick understanding of the business processes and flows.
Symbols
Although there are many symbols used proposed by various standards, but we would discuss some of the
most commonly used symbols. Understanding symbols representing functions, flows, etc may be more
readily understood by those who have some knowledge of the symbols. From a technical or academic point
of view, we have to know what symbols are used for various functions, etc.
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Table of Contents:
  1. Need for information, Sources of Information: Primary, Secondary, Tertiary Sources
  2. Data vs. Information, Information Quality Checklist
  3. Size of the Organization and Information Requirements
  4. Hierarchical organization, Organizational Structure, Culture of the Organization
  5. Elements of Environment: Legal, Economic, Social, Technological, Corporate social responsibility, Ethics
  6. Manual Vs Computerised Information Systems, Emerging Digital Firms
  7. Open-Loop System, Closed Loop System, Open Systems, Closed Systems, Level of Planning
  8. Components of a system, Types of Systems, Attributes of an IS/CBIS
  9. Infrastructure: Transaction Processing System, Management Information System
  10. Support Systems: Office Automation Systems, Decision Support Systems, Types of DSS
  11. Data Mart: Online Analytical Processing (OLAP), Types of Models Used in DSS
  12. Organizational Information Systems, Marketing Information Systems, Key CRM Tasks
  13. Manufacturing Information System, Inventory Sub System, Production Sub System, Quality Sub system
  14. Accounting & Financial Information Systems, Human Resource Information Systems
  15. Decision Making: Types of Problems, Type of Decisions
  16. Phases of decision-making: Intelligence Phase, Design Phase, Choice Phase, Implementation Phase
  17. Planning for System Development: Models Used for and Types of System Development Life-Cycle
  18. Project lifecycle vs. SDLC, Costs of Proposed System, Classic lifecycle Model
  19. Entity Relationship Diagram (ERD), Design of the information flow, data base, User Interface
  20. Incremental Model: Evaluation, Incremental vs. Iterative
  21. Spiral Model: Determine Objectives, Alternatives and Constraints, Prototyping
  22. System Analysis: Systems Analyst, System Design, Designing user interface
  23. System Analysis & Design Methods, Structured Analysis and Design, Flow Chart
  24. Symbols used for flow charts: Good Practices, Data Flow Diagram
  25. Rules for DFDs: Entity Relationship Diagram
  26. Symbols: Object-Orientation, Object Oriented Analysis
  27. Object Oriented Analysis and Design: Object, Classes, Inheritance, Encapsulation, Polymorphism
  28. Critical Success Factors (CSF): CSF vs. Key Performance Indicator, Centralized vs. Distributed Processing
  29. Security of Information System: Security Issues, Objective, Scope, Policy, Program
  30. Threat Identification: Types of Threats, Control Analysis, Impact analysis, Occurrence of threat
  31. Control Adjustment: cost effective Security, Roles & Responsibility, Report Preparation
  32. Physical vs. Logical access, Viruses, Sources of Transmissions, Technical controls
  33. Antivirus software: Scanners, Active monitors, Behavior blockers, Logical intrusion, Best Password practices, Firewall
  34. Types of Controls: Access Controls, Cryptography, Biometrics
  35. Audit trails and logs: Audit trails and types of errors, IS audit, Parameters of IS audit
  36. Risk Management: Phases, focal Point, System Characterization, Vulnerability Assessment
  37. Control Analysis: Likelihood Determination, Impact Analysis, Risk Determination, Results Documentation
  38. Risk Management: Business Continuity Planning, Components, Phases of BCP, Business Impact Analysis (BIA)
  39. Web Security: Passive attacks, Active Attacks, Methods to avoid internet attacks
  40. Internet Security Controls, Firewall Security SystemsIntrusion Detection Systems, Components of IDS, Digital Certificates
  41. Commerce vs. E-Business, Business to Consumer (B2C), Electronic Data Interchange (EDI), E-Government
  42. Supply Chain Management: Integrating systems, Methods, Using SCM Software
  43. Using ERP Software, Evolution of ERP, Business Objectives and IT
  44. ERP & E-commerce, ERP & CRM, ERP Ownership and sponsor ship
  45. Ethics in IS: Threats to Privacy, Electronic Surveillance, Data Profiling, TRIPS, Workplace Monitoring