As you've seen, creating AssemblyLines can be a pretty quick business. However, a completed AssemblyLine run does not mean that your solution is ready for 'prime time'. Even simple integration tasks warrant a minimum of both forethought and outcome analysis.
Some pertinent questions to reflect on are:
For long-running AssemblyLines, like those used for synchronizations and to power services, you can tack on additional considerations like availability and fault-tolerance, performance, scalability and security.
If you are new to Tivoli Directory Integrator then don't worry if this chapter seems complex and difficult to follow. Instead, come back and re-read these sections as your experience and comfort with the system grows.