Which boxed CRM to choose (for the implementation of complex business processes)?

Question

CRM

Gentlemen, I welcome you all!
So, there is a company, big enough. All business processes are implemented in corporate self-written CRM based on IBM Lotus. The system is not without jambs, with a huge legacy, and the bottlenecks of IBM Lotus do not allow it to be easily scaled.
A fork appears:
1) Write a competently new one, from scratch, using Symfony, Zend or RoR.
2) Buy a boxed version of the popular CRM and finish it to fit the needs of the company.
Consider the second option: we take, for example, a box from Megaplan (or a similar product).
And here the questions begin:
1) What CRM do you consider the most flexible and customizable? (1C do not offer)
2) Business processes in the company are not simple, with parallel approval of documents, many dependencies between entities. Is it possible to dig into the source code of a boxed CRM and implement these business processes there? After all, the functionality of the same Megaplan is clearly not enough to model complex processes through the system interface.
3) If the answer to the second question is "yes" - is there anyone among us with such experience? To what extent is everything smartly written and modified there? That is, I don’t want to give a few hundred thousand for a box and see a storehouse of shit code there. I did not find a help on the engine compartment mechanisms of Megaplan on their website.
Thank you in advance!

Answer 1

m.b. help
habrahabr.ru/post/204716
habrahabr.ru/post/144135

Answer 2

habrahabr.ru/post/245205 - here is a recent post about business processes, everything is well written there

Answer 3

The issue of the complexity of business processes should be closed not so much by the choice of platform as by the architecture and approach to management.
About what approaches and for what types to use - they have been arguing for more than a dozen years. A bunch of copies were broken.
A couple of years ago, working in a federal company, we asked the same question.
And there were the same problems and the same tasks. Megaplan stood, which did not save in any way.
My experience even then allowed me to understand that not a single ready-made solution would work. Too big company and too complex processes. And even the question is not in complexity, but in unpredictability. These are typical problems for large companies.
I knew for sure that I needed to look for solutions from the adaptive case management class. BPMN, WorkFlow and other ideologies will do little good. But they will gobble up millions of resources.
But at that time, nothing sensible was found. And we drank ours. Based on my experience from already implemented projects in various industries.
And then, based on those developments, the OpenSource product systemo.biz/skaz-o-tom-kak-my-dvizhok-dlya-blogov-...