The benefits of Continuous Integration cannot be discounted in any environment whether you are working on a small project or a huge one. The difference being in the set up and configuration of continuous integration in a multi-module project.
Multiple modules bring in additional complexity in terms of versions, teams collaborating, release cycles, separate sprints etc etc. In an ideal world all this would not be necessary and we would have just one module for the entire system. With every developer check-in the CI build would trigger. Of course the CI box would have unlimited processing power, load distributing capability and unlimited storage to still build the system of any size under 10 minutes.
The magic number of 10 minutes is an XP practice for CI where it is correctly stated that if a build is taking more than 10 minutes then the value of CI is lost. If the time is more developers would check in less frequently because who wants to wait for say 2 hours to get the status, they would rather check-in their code end of the day and even worse not wait for the build to complete. A broken build, which would happen many times would be fixed the next day. Now just assume that the team is distributed across time zones and are struggling with a broken build when they step into the office.
Let us switch the real world and agree that having a huge system build under 10 minutes is a far fetched dream. If you are working in a huge enterprise, where various complex systems are collaborating together then you would agree to my point.
So the best way to build a huge system is by distributing it into multiple smaller systems or modules and then building each module separately so that each module can build under 10 minutes.
Taking a simplistic view of the real world let us assume that we successfully divided our system into 3 modules.
System = Ʃ modules (A,B,C)
