MIS SPPU Unit II

1. System Engineering Analysis and
design
• When the system approach to problem solving is
applied to development of IS for business
solution it called as IS development or application
development
• System thinking is ‘ seeing the forest and the
trees’ . It involves seeing interrelationship among
systems rather than linear cause-effect for an
event. It is seeing process of change among
systems rather than snapshots of change
wherever occurring.

2. • E.g. Virtualization
• It means understanding of S/W and
application on different platforms
•

3. Systems Approach to Problem Solving
Design
the
Solution
Define
the
Problem
Develop
Alternative
Solutions
Select
the
Solution
Implement
the
Solution
MonitorandEvaluateResults

4. • The systems approach views a business
process as a system that has 5 components:
input, process, output, feedback and control.
The systems approach to problem solving uses
the systems orientation to conceptualize the
nature of the problem. Under the systems
orientation, all elements of a problem interact
with one another. Consequently, the systems
approach considers each "step" to influence
and provide feedback on every other step

5. Approaches
• Life Cycle Approach
• Object Oriented Approach

6. Define
A system is group of interrelated components
working together toward a common goal by
accepting input and producing output in an
organized transformation process

7. Type
• Natural System: human body, Galaxies etc
• Man made: Government
• Physical
• Abstract: e.g. business models
• Open: interact with environment
• Closed

8. Information system development
• When system approach is applied for
information system solutions then it is called
as Information system development

9. Traditional Systems Development Life
Cycle
Systems Implementation
Product:
Operational System
Systems Investigation
Product:
Feasibility Study
Systems Analysis
Product:
Functional Requirements
Systems Design
Product:
System Specifications
Systems Maintenance
Product:
Improved System
Understand the
Business
Problem or
Opportunity
Develop an
Information
System
Solution
Implement
the Information
System
Solution

10. • The traditional information systems development cycle
is based upon the stages in the systems approach to
problem solving, where each step is interdependent on
the previous step:
• Systems Investigation. This stage may begin with a
formal information systems planning process to help
sort out choices from many opportunities. Typically,
due to the expense associated with information
systems development this stage includes a cost/benefit
analysis as part of a feasibility study.

11. • The Investigation Phase begins the preliminary study
of the proposed information system solution to meet
the e-business needs. Its focus is to seek to answer the
questions: What are our opportunities, what are our
priorities, and can IS be used to address these needs?
• Because the process of application development can
be costly both in time and resources, the system
investigation phase begins with a Feasibility Study.
The goal of feasibility studies is to evaluate alternative
systems and to propose the most feasible and desirable
systems. Feasibility is assessed across four major
categories:

12. • Organizational Feasibility. This focuses on how
well a proposed information system supports the
objectives of the organization.
• Technical Feasibility. This ascertains whether
reliable hardware and software capable of
meeting the needs of the proposed system can
be acquired or developed.
• Operational Feasibility. This refers to the
willingness and ability of the management,
employees, customers, suppliers, and others to
operate, use, and support a proposed system.

13. • Economic Feasibility. This is concerned with whether the
proposed IS benefits are greater than its costs. This area is
particularly concerned with financial affordability --
whether the firm can pay to develop the system. A
cost/benefit analysis is used to weigh the total costs a new
system is likely to incur against the total anticipated
benefits to be gained. This includes determining tangible
costs (such as hardware and software purchases and
employee salaries) and intangible costs such as effects on
employee morale and disruptions in productivity during the
installation of the new system. Benefits too can be either
tangible (such as reduced inventory and carrying costs) or
intangible (higher customer satisfaction).

14. • Legal Feasibility

15. Systems Analysis
• It is extension of system investigation. It is in-
depth analysis of several basic activities.
Ultimately it is an indepth study of end user
information needs that produces functional
requirements

16. Cont…………….
• Organizational Analysis. An effective IS can
only be designed with a full awareness of the
organization it will serve. Systems analysis
then begins with a thorough analysis of the
organization, its management structure, its
people, its business activities, the
environmental systems it deals with, and its
current information systems.

17. • Analysis of the Present System. If a system
already exists, it is useful to study it to help
assess how it can be improved or replaced by
the proposed system. In particular, the
analysis should identify how things are
currently done (such as user interface
methods) and determine how they should be
done in the system being designed.

18. • Logical Analysis
• It is blueprint of current system that display
only what the current system does without
regard for how it does it.
• Suppose order are in inbox of executive. But
logical analysis will take it as order stored in
hard disk. Thus What part is important not
How

19. • Functional Requirements Analysis.
Functional requirements specify the
information systems capabilities required to
meet the information needs of users. In
particular, functional requirements analysis
must specify:

20. • User Interface Requirements. What user input will be needed? The
input/output needs of end users must be supported by the IS.
• Processing Requirements. Functional analysis must specify the
processing requirements necessary to perform all the activities
involved in converting input into output. The objective is to
determine what must be done; not how it will be done.
• Storage Requirements. What data must be stored and retrieved?
Organization, content, and size of databases and procedures for
maintenance must be specified.
• Control Requirements. What control reports must be produced?
What data input controls are needed? Issues of accuracy, validity,
safety, security, and adaptability must be specified.

21. Methods for assessing requirements
• Interviewing
• Brainstorming
• Questionnaires
• Quality function deployment: is a quality
management technique that translates the
needs of customers into technical
requirements

22. Joint application development
• It is an information gathering technique that
allows the project team, users and
management to work together to identify
requirements. 10 to 20 participants

23. System design
• From output of System analysis i.e. requirement
specification second phase i.e. system design
starts.
• Is the process of defining the architecture ,
components , modules interfaces and data of a
system to satisfy specified requirements.
• In logical view what is to be accomplished will be
designed (DFD, ER Etc)
• In physical view how it will be accomplished will
be design (Hardware, software,etc)

24. System Design
Phase of detailing how a system will meet the information
requirements determined by the systems analysis. This phase is
broken into two sub phases:
1. Logical design 1st phase, lays out the components of the
information system and their relationship to each other as they
would appear to users.
2. Physical design 2nd phase, the process of translating the abstract
logical model into the specific technical design for the new system
Tools and Techniques used for designing:
Flow Chart Dataflow Diagrams (DFDs)
Data Dictionary Structured English
Decision Table Decision Tree
Design specifications include: Output, Input, User interface, Database
design, Manual procedures , Documentation etc..

25. System design
USER
Interface
Design
Data Design
Process
Design
Screen Form and
dialog design
Data element
and structure
design
Program and
procedure design

26. objectives
• Practicality
• Flexibility
• Efficiency
• Security

27. Two level of design
• Conceptual design helps in generating
alternative MIS designs and help in selecting
one.
• This selected one is further given shape of
detailed MIS design

28. Conceptual design
• Define Problem
• Set system objectives
• Identify constraints (by customers, government ,
suppliers, management, money etc)
• Determine information needs and sources
• Develop various designs (alternatives)
• Documentation of selected design (overall flow,
input, output)
• Report preparation

29. Detailed system design
• Project planning and control :should be
considered as a project for efficiency
• Involve the user
• Detailed sub system definition
• System-- subsystem->function-> task->
operational element
• Output/Input design
• Forms, formats etc of output and input

30. • Feedback once again from user
• Database design
• Procedure design for data entry, run time
procedures( e.g. to load printer with specific
paper), error handling procedure, security and
backup procedures, software documenting
procedures
• Design documentation

31. Implementation
• First step is to plan
• Acquiring facilities and space
• Developing organization mindset for MIS and its
procedures
• Acquiring hardware and software
• Coding
• Testing
• Creation of forms and database
• Documentation
• User training

32. Installation
• Conversion of old into new
• Parallel: run old and new simultaneously
• Pilot(modular): Install in one part at a time
• Phased: implement in one of function
• Cutover (direct) : start directly with new
system

33. Evaluation and Maintenance
• On basis of timeliness, relevance, accuracy,
completeness, adequacy, exception-bases
• Cost-benefit evaluation
• Maintenance: the process of monitoring,
evaluating, and modifying of existing
information systems to make required or
desirable improvement may be termed as
system maintenance.

34. • Corrective Maintenance
• Adaptive
• Perfective: adding new programs or modifying
existing programs