1. Software Reuse Objectives
To explain the software reuse, its benefits and some reuse problems
To describe different types of software reuse and how they can be incorporated into the software development at various levels

2. Reuse-based software engineering
Application system reuse
The whole of an application system may be reused either by incorporating it without change into other systems or by developing application families
Component reuse
Components of an application from sub-systems to single objects may be reused
Function reuse
Software components that implement a single well-defined function may be reused

3. Types of Software Reuse
Ad-hoc reuse
Intra-Project reuse
Inter-Project reuse
Enterprise-level reuse
Horizontal Reuse
Vertical Reuse

4. Component development for reuse
Components for reuse may be specially constructed by generalising existing components
Component reusability
Should reflect stable domain abstractions
Should hide state representation
Should be as independent as possible
The more general the interface, the greater the reusability

5. Reusable components
The development cost of reusable components is higher than the cost of specific equivalents.
This extra reusability enhancement cost should be an organization rather than a project cost
Generic components may be larger and slower than their specific equivalents

6. Reusability standards
Name generalisation
Operation generalisation
Exception generalisation
Component certification

7. Reusable Component Design

8. Application families
An application family or product line is a related set of applications that has a common, domain-specific architecture
The common core of the application family is reused each time a new application is required
Each specific application is specialised in some way
Application family architectures must be structured in a way that separates different sub-systems and allows them to be modified

9. Application family specialisation
Platform specialisation
Different versions of the application are developed for different platforms
Configuration specialisation
Different versions of the application are created to handle different peripheral devices
Functional specialisation
Different versions of the application are created for different customers

10. Training and incentives for reuse
Specialized training of the staff is very essential
People should be convinced about the concept behind reuse and its benefits
Providing incentives to the individuals who contribute to the reuse initiative
Long term vs. short term benefits

11. Benefits of reuse Increased reliability Reduced process risk
Components already tested
Reduced process risk
Less uncertainty in development costs
Effective use of specialists
Reuse of components instead of people
Standards compliance
Accelerated development

12. Reuse problems Lack of tool support Maintaining a component library
Finding and adapting reusable components
No planning for reuse
Reuse confined to an individual or within one system
Limited to code-level reuse
No or negative reuse incentives
Cost of reuse is too high
Inability to recognize what has high potential for reuse
No reuse activities defined as part of the software life cycle process