Objective measure of the degree to which multiple services are integrated

I need help sorting out some issues and perhaps on some statistical matters.

I'm working with a business that provides services.  Let's call them
Service A and Service B.  Internally, the business is segmented, for
most purposes, into categories based on services (i.e., there's
Service A, B, C, D, etc., and the employees who provide Service A
don't have much to do with the employees who provide Service B and so
on).  Some in the business believe total revenue (or maybe profit) is
enhanced when employees who provide Service A and employees who
provide Service B work together on common clients and when they go
after new clients as a team.  Let's call such common efforts
integration.  Maybe the client perceives that this comprehensive or
integrated approach has value.  Maybe it's just that clients buy more
in total when the business tries to sell them multiple services in a
unified or integrated way rather than having the Service A guys and
the Service B guys making their pitches independently.  Maybe
integrating services doesn't actually provide more total revenue (or
profit).

I want to find a measure of the degree of integration for a given
client.  As I see it, a measure of this sort could be objective or
subjective.  This is a request for help with an objective measure, but
I'll say a few words about a subjective measure so you'll know what
I'm not asking for here.


Measure of Subjective Integration

	Here I'm thinking of things similar to indicies of customer
satisfaction.  I'm not ready to ask for help on this part yet.  I need
to think about it a bit more.  I guess my point is that this posting
is not asking for things like, "Ask leaders on a 7-point scale to rate
their agreement with the following statements" and then have a list of
things like, "Service A and Service B were appropriately integrated
for this client."


Measure of Objective Integration

	The data currently available for developing measures of integration include

* geographic region for client,
* annual revenue from Service A and Service B for the last couple of
years and in many cases subservice revenue, which I'll call products
(i.e., products would be Service A1, A2, ..., Service B1, B2 ...), and
* service leader names (i.e., Service A leader, Service B leader, and
overall leader if both are provided to the client).

I may have or could obtain other information.  The point is, I'm not
even sure how to measure integration objectively.  I've toyed with a
few possibilities, but I won't bias you with my thoughts on this.  I'd
like for you to take a fresh look.


Deliverables

* 2-5 links to documents that address issues related to integration -
preferably about how to objectively measure the degree of integration
for individual clients.  I'm not optimistic such measures exist.  If
any measures of integration do exist, I'd like links that help me
understand the strengths and weaknesses and similar information about
these existing measures.  If, as I suspect, there are no measures in
general use, I'd like the links to help me understand more about the
nature of integration, especially how to tell when there is more
integration and when there is less integration for a given client. 
Such links might venture off into discussions of subjective
integration.

* 2-5 objective measures - the above might provide this information,
which is what I'd really like, but as I'm not optimistic about that,
I'd like for you to come up with some possibilities.  These might be
ratios or ... I don't know what you might think of to measure
integration objectively.