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)