One of the often-repeated reasons for not starting a reuse program is the upfront investment required for building the initial set of reusable assets. This is a legitimate impediment that can be addressed by taking advantage of existing code in your team. When you evaluate existing assets for their reuse potential, there are a lot of factors to consider. Here are a few salient ones:
- Fit within product line: is the asset of relevance to one or more applications in your domain? You want to invest in assets that encapsulate business functionality that can be utilized in multiple business processes and applications. Similarly, if there are assets with business relevance but in a area that your organization intends to divest out of – you will be less inclined to use them.
- Coupling: How tightly or loosely coupled are the pieces within an asset? sometimes the asset itself might be mixed in – tightly coupled – with a lot of extraneous code. Business logic might be mixed with data access, presentation, and even specific calls to external systems. Every one of these aspects introduces coupling that will need to be assessed thoroughly.
- Integration: what is the effort required to integrate the reusable asset with applications? The asset might be very difficult to integrate because of platform specific requirements or because of language needs.
- Business Assumptions: are there assumptions that the asset makes about business rules or business activities? if so, are these assumptions still relevant? will the rules need externalization/refactoring? Often, business assumptions are lost due to lack of alignment between business concepts and abstractions in code.
In a followup post, I will elaborate on robustness, scalability, deployment, documentation & samples. Without thinking through these aspects it is risky to introduce new assets for reuse. You will quickly discover that your consumers are unforgiving when it comes to asset quality. Additionally, a huge learning curve will drive away potential and existing developers and technical leads from evaluating assets for use with new applications.