Like any other engineering discipline, software engineering can gain a lot from a solid discipline of reuse. But unlike other engineering disciplines, software asset reuse does not come naturally in software engineering. When it does, it never comes without costs and risks.

Possible reusable asset categories:
- Requirements / Specifications
- Documentation
- Designs
- Architectures
- Source Code
- Test Data
- Executable Code

Software asset reuse starts by being a cultural thing. Managerial aspects play a critical role in it. Software asset reuse cannot happen without strong commitment from the managerial structure of the development organization.

Reuse Libraries and DSM (Domain-Specific Modeling)

We can consider two types of reuse libraries: Horizontal and Vertical.

An horizontal library augments the expressive power of the language without commiting to a specific application domain. It has the advantage of being useful across several projects, but it is limited to around 20% of the application’s total code.

A vertical library contains domain-specific components, and can reduce the amount of coding we need to produce by up to 65%. The drawback is that it can only be used within a single application domain, and hence potentially few projects

If we map these two types of libraries to the DSM paradign, we can say that an horizontal library lies on the solution domain, and a vertical library lies on the problem domain.