This document discusses component-based software development and reuse. It defines what a software component is, how components are composed into systems, and the idealized component lifecycle from design to deployment and execution. It also addresses challenges such as what to do if a repository of existing components is empty, and provides strategies like implementing new components, searching external repositories, or extracting components from requirements. Key component models and approaches are also summarized such as the Manchester "X-MAN" model.

1. REUSE IN
COMPONENT-BASED Simone Di Cola
SOFTWARE Supervisor: Kung-Kiu Lau
DEVELOPMENT

2. THE SOFTWARE CRISIS
“ […] now we have gigantic computers,
programming has become an equally gigantic
problem.”
Edsger Dijkstra
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3. THE PERVASIVENESS OF
SOFTWARE
Scalability
Complexity
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4. COMPONENT-BASED
SOFTWARE DEVELOPMENT
Reposito
ry
A System System
X Y
B A D A
C
B C B C
D
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5. WHAT IS A COMPONENT?
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6. COMPONENTS COMPOSITION
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7. GENERIC COMPONENT
Provided
service
Implementatio
n
Required
service
Provided
service
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8. COMPONENT DEFINITION
Szyperski Meyer Heineman
“A software “A component is a “A [component is a]
component is a unit software element software element
of composition with satisfying the that conforms to a
contractually following component model
specified interface conditions: and can be
and explicit context It can be used by independently
dependencies only. other software deployed and
A software elements; It composed without
component can be possesses an modification
deployed official usage according to a
independently and description, which composition
is subject to is sufficient for a standard. [3]”
composition by client author to use
third parts. [1]” it; It is not tied to
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any fixed set of

9. SOFTWARE COMPONENT
MODEL
DEFIN
ES
COMPONENT COMPOSITION
Syntax Mechanism
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10. WHY OBJECTS ARE NOT
ENOUGH? [4]
Difficult Tight
to reuse coupling
Lack of Hard to
structure verify
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11. THE MANCHESTER WAY – X-
MAN [6]
Atomic Composition Composite
component connector component
In X-MAN control and computation are separated
I
U
This leads to highly factored system design
Unit
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12. IDEALIZED COMPONENT
LIFE-CYCLE [5]
Design phase Deployment phase Execution phase
Builde Reposito componen Run-time
Assembler
componen componen
r ry t (binary) t
t (source)
(instance)
A A
A
A Instance
B B
B
B Instance
design Cdeployme D
phase nt phase D
C Instance
compositi compositi
on D on BC
BC
operator operator Instance
BC

13. WHAT IF MY REPOSITORY IS
EMPTY?
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14. POSSIBLE STRATEGIES
Implement
Search
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15. IMPLEMENT
Extracting
component from
Natural Language
Requirements
Model-driven Incremental &
Component- Iterative
based component
development development
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16. SEARCH
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17. USING THE WEB AS A REUSE
REPOSITORY [7]
Stack
+push(o:Object):vo
id
+pop(void):Object
Describe Describe Search Match
Compile Test
syntax Semantics the web signature
Stack stack1 = new Stack();
Stack1.push(“Lessie”);
assertTrue (((String)
stack1.pop().equals(“Lessie”));
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18. THANK YOU!
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19. REFERENCES
[1] C. Szyperski, D. Gruntz, and S. Murer. Component Software: Beyond Object-Oriented
Programming. Addison-Wesley, second edition, 2002.
[2] B. Meyer. The grand challenge of trusted components. In Proc. ICSE 2003, pages
660–667. IEEE, 2003.
[3] G.T.Heineman and W.T.Councill, editors. Component-Based Software Engineering:
Putting the Pieces Together. Addison-Wesley, 2005.
[4] C. Pfister and C. Szyperski. Why objects are not enough. Proceedings of 1st
International Component Users Conference. SIGS Publishers, 1996.
[5] K.-K. Lau and Z. Wang. Software Component Models. IEEE Transactions on
Software Engineering 33(10):709-724, 2007.
[6] K.-K. Lau and C.M. Tran. In Proceedings of 38th EUROMICRO Conference on
Software Engineering and Advanced Applications, pages 158-165, IEEE, 2012.
[7] Hummel, O. & Atkinson, C. Using the web as a reuse repository. Reuse of Off-
the-Shelf Components, pp.298–311, 2006.
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