The document discusses concepts of coupling and cohesion in software engineering. It defines coupling as the measure of independence between components and notes that highly coupled systems have strong interdependencies, while loosely coupled and uncoupled systems have fewer or no dependencies. Cohesion refers to how closely related the parts of a component are, ranging from coincidental to sequential cohesion. The document provides examples to illustrate different types of coupling like content, common, control, stamp and data coupling.

1. Presentation
Of
Software engineering
Topic : Cohesion & Coupling
Jagnesh
Chawla(jagneshchawla@gmail.com)

2. Contents :
 Coupling
 Highly Coupled
 Loosely Coupled
 Uncoupled
 Types Of Coupling
 Cohesion
 Types Of Cohesion
Jagnesh
Chawla(jagneshchawla@gmail.com)

3. Coupling
 Coupling is measure of the
independence of components.
 Coupling is related to cohesion.
 It is an indication the strength of inter
connections between the components
in a design .
Jagnesh
Chawla(jagneshchawla@gmail.com)

4. Highly coupled
 These types of systems have
interconnections , with program units
dependent on each other.
Jagnesh
Chawla(jagneshchawla@gmail.com)

5. Highly coupled:
Jagnesh
Chawla(jagneshchawla@gmail.com)

6. Loosely coupled
 Loosely coupled systems are made up
of components which are independent
or almost independent.
 In this less dependences are
available.
Jagnesh
Chawla(jagneshchawla@gmail.com)

7. Loosely coupled:
Jagnesh
Chawla(jagneshchawla@gmail.com)

8. Uncoupled
 Uncoupled components have
interconnections at all.
 No Dependencies
Jagnesh
Chawla(jagneshchawla@gmail.com)

9. Uncoupled:
Jagnesh
Chawla(jagneshchawla@gmail.com)

10. The range of coupling
measures:
Content coupling High coupling
Common
coupling
Loose
Control coupling
Stamp coupling
Data coupling Low
Uncoupled
Jagnesh
Chawla(jagneshchawla@gmail.com)

11. Content coupling:
 When one component actually
modifies another .
 Then the modified component is
completely dependent on the
modifying one.
Jagnesh
Chawla(jagneshchawla@gmail.com)

12. Jagnesh
Chawla(jagneshchawla@gmail.com)

13. Common coupling:
 We can reduce the amount of coupling
somewhat by organizing our design so
that data are accessible from a
common data store.
Global:
A1
A2
A3
Variables:
V1
V2
Component Component
Component
X Y
Z
Change V1 Increment T T
V =V2+A
To zero V1
Jagnesh
Chawla(jagneshchawla@gmail.com)

14. Control coupling:
 When one component passes
parameters to control the activity of
another component.
 We say that there is control coupling
between the two.
Jagnesh
Chawla(jagneshchawla@gmail.com)

15. Stamp coupling:
 When data structure is used to pass
information from one component to
another.
Jagnesh
Chawla(jagneshchawla@gmail.com)

16. Data coupling:
 If only data are passed, the
components are connected by data
coupling.
Jagnesh
Chawla(jagneshchawla@gmail.com)

17. Cohesion:
 The cohesion of a component is a
measure of the closeness of the
relationship between its components.
Jagnesh
Chawla(jagneshchawla@gmail.com)

18. Coincidental:
 The worst degree of cohesion,
coincidental is found in a component
whose parts are unrelated to one
another.
Jagnesh
Chawla(jagneshchawla@gmail.com)

19. Logical cohesion:
 It is the next higher level of cohesion ,
where several logically related functions
or data elements are placed in same
component.
Jagnesh
Chawla(jagneshchawla@gmail.com)

20. Temporal cohesion:
 Sometime a component is used to
initialize a system or a set variables.
 Such a component performs several
functions in sequence ,but the
functions are related by the timing
involved, so its cohesion is temporal.
Jagnesh
Chawla(jagneshchawla@gmail.com)

21. Procedurally cohesion:
 When function are grouped together in a
component just to ensure this order the
component is procedurally cohesive.
Jagnesh
Chawla(jagneshchawla@gmail.com)

22. Communicationally:
 Communicationally cohesion often
destroys the modularity and functional
independence of the design.
Jagnesh
Chawla(jagneshchawla@gmail.com)

23. Sequential cohesion:
 If the output from one part of a
component is input to the next part the
component has sequential cohesion.
Jagnesh
Chawla(jagneshchawla@gmail.com)

24. Thank you ……
Jagnesh
Chawla(jagneshchawla@gmail.com)