Web Development

I am looking for a smart way to structure our development environments. Currently we 'branch' a new development environment for each new client. This allows us to develop customisations for the client, and manage the periodic releases during implementation projects.

However, we also have a Base version (from which new releases previously mentioned are cloned) from which we create software revisions and releases. Theoretically, customizations made in client environments are integrated intothe Base system once the implementation project is complete.

Time and money constraints often mean that code integration to Base is not performed in a timely fashion. Two problems emerge because of this situation:

1. Work (for example bug fixes) already performed in Base need to be duplicated in client environments (because a client changes have not been integrated into base so a patch can not be issued); and

2. Work preformed in a client system needs to be performed in another clientsystem because (because a client changes have not been integrated into base a copy of base has to be augmented with the changes).

We are considering moving to a system in which there is only one environment in which development work takes place (Base). However I am concerned that we will experience issues with contention for code objects, etc.

Does anyone have feedback or advice on how we can rationalize the effort that we invest in internal code merging and management? How can we best balance effort spent moving code between environments with considerations like conflict for source code objects?