What is CTP (Capable-to-Promise)?
CTP determines whether a customer order can be fulfilled by a requested date by checking material availability and production capacity, not just existing inventory.
Definition
Capable-to-Promise (CTP) extends order promising beyond on-hand and scheduled stock by evaluating whether additional supply could be created in time using available production capacity and component materials. It is essential in make-to-order and configure-to-order environments where the answer to a delivery promise depends on shop-floor capacity and supply lead times. CTP typically requires more sophisticated planning logic than ATP because it simulates production. The result is a realistic delivery date that accounts for what the operation can actually build.
How CTP Works in ERP
When a standard ATP check cannot satisfy an order, the ERP or advanced planning system runs a CTP simulation that explodes the bill of materials, checks component availability, and tests finite capacity to find a feasible build and delivery date. The system returns the earliest date the order can be met given those constraints. CTP is usually delivered through APS modules tightly integrated with order entry, MRP, and capacity planning.
ERP Vendors with Strong CTP
Frequently Asked Questions
When do I need capable-to-promise instead of available-to-promise?
ATP is sufficient when you sell from stock or already-scheduled supply, but make-to-order and configure-to-order businesses often have no finished inventory to promise from. In those cases CTP is needed to evaluate whether materials and capacity can produce the order by the requested date. CTP gives a realistic promise where ATP would simply report nothing available.
Why does CTP require advanced planning capabilities?
CTP must simulate production by checking component availability, exploding the bill of materials, and testing finite capacity across work centers. This is far more computationally involved than ATP's inventory netting. As a result it is typically provided by APS engines integrated with the ERP rather than by basic inventory logic.