Few ERP systems are implemented out-of-the-box as some additional development is almost always necessary and this by its nature complicates projects and is risky:
The development activity is always where much additional, often unanticipated, project cost is added.
This phase primarily involves the Delivery and Vendor teams working together in order to:
Close collaboration is required during the specification and testing activities between the Delivery and Vendor teams.
A robust development management process is essential:
Without a robust development process, it is easy for project costs to spiral out of control.
Ticketing, Change Control and Kanban boards are commonly used during the development phase.
You may be compelled to use the development apps favoured by your vendor.