1. Nazia manzoor 07, Sumaira akbar 14, Anum Gill 18
Amna nawaz 24, Maria shahid 48, Amara zafar 53
Group no. 4
BBA HONS MORN 8th, 2010-2014
System theory and methodologies
System theory and methodologies1

2. Systems are elements in interaction it is also a
management methodology as it is a way of
analyzing and thinking about organization
Systems Theory Definition
System theory and methodologies2

3. Systems Types: Open Vs. Closed
 An open system interacts with its environment.
 A closed system receives no inputs from its
environment & entropy or decay sets in.
 Systems have different levels of being open or
closed.
 A variety of inputs is required to help a system to
remain open.
 Implications
 Need to create as open a system as possible to
avoid entropy
System theory and methodologies3

4. Systems Concepts:
 hierarchy
Systems are nested in a hierarchy, that is, systems
consist of subsystems and systems operate within
environments
 Boundaries
Boundaries are the interface between a system and its
subsystems or a system and its environment
 Inputs
All systems have:
Inputs  processes  output 
 Criteria (feedback loop) 
System theory and methodologies4

5. System development methodology
A system development methodology refers to the
framework that is use to structure plan and control
the process of developing an information system.
Types of methodologies (to develop an IS)
 Waterfall method
 prototyping
 rapid application development RAD
System theory and methodologies5

6. Structured methodology
(“Waterfall”)
System theory and methodologies6

7. Waterfall Model
Waterfall is a linear approach to software
development. In this methodology, the sequence of
events is something like:
 Requirements
 Design
 Implementation
 Verification
 Maintenance
System theory and methodologies7

8. Waterfall Model (Conti.)
 In a true Waterfall development project, each of these
represents a distinct stage of software development,
and each stage generally finishes before the next one
can begin. There is also typically a stage gate
between each; for example, requirements must be
reviewed and approved by the customer before
design can begin.
System theory and methodologies8

9. Prototyping Model
 Prototyping
 Building a scaled-down working version of the
system (i.e. a prototype)
System theory and methodologies9

10. Prototyping Model (Conti.)
Prototyping is an attractive idea for complicated
and large systems for which there is no
manual process or existing system to help
determining the requirements. The prototype
are usually not complete systems and many
of the details are not built in the prototype.
The goal is to provide a system with overall
functionality.
System theory and methodologies10

11. RAD = Rapid Application Development model
System theory and methodologies11

12. Phases in RAD Model
the phases in the rapid application development
(RAD) model are:
Business modeling:
The information flow is identified between various
business functions.
Data modeling:
Information gathered from business modeling is used
to define data objects that are needed for the
business.
.
System theory and methodologies12

13. RAD Model (Conti.)
Process modelling:
Data objects defined in data modelling are
converted to achieve the business information flow
to achieve some specific business objective.
Description are identified and created for CRUD of
data objects
Application generation:
Automated tools are used to convert process models
into code and the actual system.
Testing and turnover:
Test new components and all the interfaces.
System theory and methodologies13

14. RAD Model (Conti.)
RAD model is Rapid Application Development
model.
 In RAD model the components or functions are
developed in parallel as if they were mini projects.
The developments are time boxed, delivered and
then assembled into a working prototype. This can
quickly give the customer something to see and
use and to provide feedback regarding the delivery
and their requirements.
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15. Model of Information system of the firm
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16. Why use Information Systems in firms?
 Each group in a firm has different need for information
 Operational Excellence
 Productivity
 Efficiency
 Agility
 Develop New Product and Services
 Attain Customer Intimacy and Service
 Improve Decision Making
 Accuracy
 Speed
 Promote Competitive Advantage
 Ensure Survival
System theory and methodologies16