Evaluate functional specifications and create technical design documentation
To understand the requirements for developing customizations for your implementation, you need to address the effects of implementing a new feature and how it might affect current functionality. You need to understand existing processes and compare how you'll need to implement them in the new system.
These processes shouldn't be about the business requirements, but rather, be centered on the current state and how enhancements or changes will affect the overall system during the implementation. To design a new functional process, determine the needs and make sure that you know the step-by-step process to complete this development.
For example, if you have procurement processes that you want to automate and don't currently use, you need to consider this new feature with the current state of the project and how it affects the other aspects of the system.
When you design the documentation for the functional specifications, the more detailed the specifications are, the better idea you'll have of the effort involved for the customizations and development.