Is it possible to create a mutual relationship between full-time work and a PhD program? Having experienced academia through masters, and work via part-time and full-time jobs, I plan to pursue PhD and keep working full time. However, my plan is to create a mutual relationship between work and PhD program in which research feeds work and leads new assignments, and work assignments helps research through results and my employer as well.


I am not sure about the case in the other fields, but I think this should be valid for CS people. Do you think or know whether this is possible? If so, do you know any examples of such programs or people who work in this particular way? 
The other questions is how might this relationship help or hurt PhD studies?


There is already a question about possibility of working full-time and pursuing PhD simultaneously. However, this question considers working in a completely unrelated area with respect to PhD program.

There is another question that explores the possibility of working on extra activities such as start-up project while pursuing PhD.
It is not unheard of to have people work outside of an academic setting on their PhD thesis. For instance, in the US national laboratory system, there are a number of graduate students working on their PhD thesis. It's not a large number—maybe a dozen or so per laboratory—but it's not zero, either. In countries such as Germany and the Netherlands, it is also not uncommon to be employed as a PhD student in industry; however, the financing of that is somewhat unclear to me. (They may receive the equivalent of their stipend, or they may receive a "professional" salary.)

That said, I suspect it will be difficult to find an arrangement which will allow you to work full-time and receive both a graduate stipend and a full-time salary. Such arrangements would be generally frowned upon by both university and the external sponsor.