Finally, for the same reason as a core subdomain, a generic subdomain can turn into a supporting one. Going back to the example of BuyIT’s document management sys‐ tem, assume the company has decided that the complexity of integrating the open source solution doesn’t justify the benefits and has resorted back to the in-house sys‐ tem. As a result, the generic subdomain has turned into a supporting subdomain.

The changes in subdomains we just discussed are demonstrated in Figure 11-1.

Figure 11-1. Subdomain type change factors