Iam not sure if this topic is ok to ask, but we are talking about this since years in our Developer-"Shop". How to write concepts for Web- Applications?

We are using Zend Framework (MVC), OOP Based, Databases, LDAP and such stuff. But no one ive ever meet can show me an good example for some kind of "technical conception". 

Goal: Write an document, hand it our to an 2nd person with "some" knowledge about our systems and good PHP 5/Zend Framework skills. Now he must be able to code without many questions to the architect.

Is it possible that this is not common in the "web scene"? Does everyone is just hacking code till the application works? 

If someone knows some good papers, examples .. Some keywords to think about:

* ERM
* UML