[P4] Using P4 to help control build breakage

[Africa, William]

The current process for SCM builds consists of daily overnight build.  There
can be a multitude of changesets from one build to the next.  And, it is the
developer's responsibility to verify that his/her checkin will not break any
other component in the build.  The process is to sync to the tip and rebuild
with your changes.  Although it is easy and fast to verify your changeset
will not break the build within your local component, it is another story
whether it will not cause problems in other areas.  The problem is that a
complete rebuild takes over 2 hours.   Thus, developer is suppose to either
sacrifice 2 hours every time to verify his/her checkin or let the SCM
overnight build catch any errors.  In addition, other developers may be
checking onto the tip while someone else is rebuilding (for 2 hours) what
was the tip at the time he/she kicked off their rebuild.  Neither
development nor SCM can be guaranteed a reliable set of source at any point
in time with the exception of the labeled overnight build.   As a result,
there is a high frequency of build breakage and low confidence in syncing to
the tip.  Also, SCM frequently delivers late to releases to QA thus delaying
their time to begin testing.

Has anyone had a similar problem?  If so, how was it resolved?  Did anyone
try a code promotion model to solve this?  I've heard source control systems
like ClearCase can track build dependencies and supply users with derived
files (such as OBJs, PDBs, EXEs, etc.) when a user wants to sync to a
verified set of source.  Has anyone explored getting a similar
implementation in Perforce?