Knowing that the most reasonable way to SOA adoption is a gradual and consecutive process [ARS08], the benefits of using a maturity model to describe and support this process become apparent. Because of this apparent applicability many maturity models for SOA exist. Some are more focused on operating a SOA and some adhere to the particular needs when introducing a SOA such as the Open Group Service Integration Maturity Model (OSIMM). Although many vendors have created their own SOA maturity model in the past, some of them are now collaborating to create vendor and technology neutral SOA maturity models (e.g. Hewlett Packard contributing to OSIMM). A list of available SOA maturity models can be found at [INQ08]. 

The SOA Maturity Model is presented because there is hardly any literature not mentioning it when it comes to SOA maturity models and most of the vendor specific models based on CMMI show similarities to it (e.g. Oracle maturity model, HP maturity model). Nevertheless, some vendor specific maturity models provide a detailed list of criteria for each maturity level which also show interesting thoughts.  

OSIMM combines the advantages of a truly independent SOA maturity model and experience of leading companies in terms of SOA integration such as Capgemini, EDS and IBM [TOG09]. 

However, both of the maturity models can provide useful assistance to a SOA adoption.