No relation between testing & CMMI. CMMI is a process improvement approach . This can be applied in any context (CMM) Testing as such is the process to find defects in an application.Knowledge about CMMI is additional benefit for testers.
Capability Maturity Model Integration developed by the SEI. It's a model of 5 levels of process 'maturity' that determine effectiveness in delivering quality software. It is geared to large organizations such as large U.S. Defense Department contractors. However, many of the QA processes involved are appropriate to any organization, and if reasonably applied can be helpful.
In my opinion CMMI and Testing are both completely difft concepts.
Testing is all about maintaining quality an the product conformance with the product specifications.
CMMI is actually a standard awarded to an IT firm for the quality of products, by SEI.
I think, there's no direct relation between the two.
Capability Maturity Model Integration (CMMI) is a process improvement approach whose goal is to help organizations improve their performance. CMMI can be used to guide process improvement across a project, a division, or an entire organization. Currently supported is CMMI Version 1.3.