Capable-to-Promise (CTP) is a real-time availability check that determines whether a new customer order can be fulfilled by a specific date by simultaneously evaluating production capacity, raw material availability, and transportation resources—not just on-hand inventory. Unlike Available-to-Promise (ATP), which only checks uncommitted stock, CTP dynamically simulates the entire manufacturing and logistics pipeline to generate a feasible, resource-constrained delivery commitment.
Glossary
Capable-to-Promise (CTP)

What is Capable-to-Promise (CTP)?
Capable-to-Promise (CTP) is a deterministic order promising logic that extends beyond static inventory checks to dynamically evaluate the availability of production capacity, raw materials, and transportation resources before committing to a delivery date.
When an order is entered, the CTP engine performs a multi-resource finite capacity check against the master production schedule, bill of materials, and routing plans. If current resources are insufficient, the system calculates the earliest possible date by modeling lead times for component procurement, machine scheduling, and outbound shipping. This prevents overpromising and ensures that every committed date is backed by a verified, executable supply chain plan.
Core Characteristics of CTP
Capable-to-Promise (CTP) extends the basic Available-to-Promise (ATP) check by evaluating not just on-hand inventory, but also the simultaneous availability of production capacity, raw materials, and transportation resources to guarantee a delivery date.
Multi-Resource Constraint Evaluation
Unlike ATP, which only checks uncommitted inventory, CTP performs a simultaneous multi-resource feasibility check. The algorithm verifies the availability of production capacity (machine hours, labor), raw materials (dependent demand), and transportation slots before committing to an order. This prevents the 'siloed promise' problem where inventory exists but cannot be produced or shipped in time.
Finite Capacity Scheduling Integration
CTP is deeply integrated with the Master Production Schedule (MPS) and shop floor calendars. It does not assume infinite capacity. Instead, it loads the new order onto a finite model of the factory to calculate a realistic completion date. Key inputs include:
- Routings: The specific sequence of work centers required
- Bill of Materials (BOM): The precise component structure
- Shift calendars: Available working hours and maintenance windows
Dynamic Lead Time Calculation
CTP systems dynamically calculate cumulative lead times by exploding the BOM and offsetting for queue, setup, run, and transit times at each level. This is not a static lookup; it is a real-time backward scheduling exercise from the requested delivery date. If a component has a 3-day lead time and assembly takes 1 day, the system verifies capacity 4 days before the ship date.
Alternative Sourcing Logic
Advanced CTP engines incorporate substitution rules and alternative routings. If the primary work center is overloaded, the system can automatically evaluate an alternate production line. If a specific raw material is constrained, it can check for an approved substitute component. This ensures the promise is made against the best feasible path, not just the default path.
Real-Time Order Promising
CTP is designed for synchronous, real-time execution within an Order Management System (OMS). When a customer service representative enters an order, the CTP engine returns a reliable promise date within seconds. This requires high-speed in-memory processing of the supply chain model to avoid latency in the sales cycle.
CTP vs. ATP: Scope Comparison
The fundamental distinction lies in the scope of the check:
- ATP: 'Do we have it?' (Uncommitted inventory only)
- CTP: 'Can we make it and move it by that date?' (Inventory + Capacity + Materials + Transport) CTP is essential for Make-to-Order (MTO) and Configure-to-Order (CTO) environments where finished goods inventory does not exist before the order.
CTP vs. ATP: Key Differences
A comparison of the resource dimensions evaluated by Available-to-Promise (ATP) and Capable-to-Promise (CTP) when committing to a customer delivery date.
| Feature | Available-to-Promise (ATP) | Capable-to-Promise (CTP) |
|---|---|---|
Primary Constraint Checked | Uncommitted on-hand and planned inventory | Inventory, production capacity, and material availability |
Scope of Evaluation | Single echelon (finished goods) | Multi-echelon (raw materials, WIP, finished goods) |
Production Capacity Considered | ||
Raw Material Availability | ||
Transportation Lead Time | ||
Calculation Complexity | Database query | Finite capacity scheduling and BOM explosion |
Response Time | < 1 sec | 1-30 sec |
Typical Use Case | Make-to-stock (MTS) environments | Make-to-order (MTO) and configure-to-order (CTO) environments |
Frequently Asked Questions
Clear, technically precise answers to the most common questions about Capable-to-Promise (CTP) logic, its mechanisms, and its role in multi-echelon order fulfillment.
Capable-to-Promise (CTP) is a real-time order promising algorithm that determines whether a specific customer order can be fulfilled by a requested date by simultaneously checking the availability of on-hand inventory, unallocated production capacity, and required raw material components. Unlike a simple Available-to-Promise (ATP) check that only looks at finished goods stock, CTP dynamically evaluates the entire supply chain's ability to produce and deliver. When an order is received, the CTP engine performs a multi-resource availability check: it explodes the bill of materials (BOM) to verify component availability, checks the finite production schedule for an open time slot, and confirms transportation resources. If any constraint fails, the system calculates the earliest feasible date by simulating the completion of upstream activities, providing a reliable, capacity-feasible delivery promise.
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Related Terms
Capable-to-Promise (CTP) is part of a broader ecosystem of order promising and inventory optimization strategies. These related concepts define how enterprises commit to delivery dates and manage the resources required to meet those commitments.
Available-to-Promise (ATP)
The foundational availability check that CTP extends. ATP calculates the uncommitted portion of on-hand inventory and planned production to provide a delivery date. It answers 'Can we ship from what we have or are already making?' but ignores whether we could make more.
- Scope: On-hand stock + existing scheduled receipts
- Limitation: Does not consider unplanned capacity
- Result: A simple 'yes' or 'no' with a date
Multi-Echelon Inventory Optimization (MEIO)
The holistic network strategy that CTP queries. MEIO simultaneously optimizes stock levels across all nodes—suppliers, central warehouses, regional hubs—to minimize total system cost. A CTP check fails if MEIO has not correctly positioned safety stock to buffer against variability.
- Goal: Right part, right place, right quantity
- Input: Demand variability, lead times, service level targets
- Linkage: CTP is the execution arm of an MEIO strategy
Order-Up-To Level
The maximum target inventory position used in periodic review policies. When a CTP check consumes available resources, it drives the inventory position below this order-up-to level, triggering a replenishment order to restore the buffer.
- Formula: Expected demand during (lead time + review period) + safety stock
- Function: Defines the ceiling for inventory replenishment
- Interaction: CTP deducts from this target; the system re-orders to it
Stochastic Programming
The mathematical engine behind advanced CTP. Stochastic programming models future uncertainty—like machine breakdowns or supplier delays—as a set of probabilistic scenarios. It finds a single promise that is feasible across the weighted average of all possible outcomes.
- Purpose: Make robust commitments under uncertainty
- Method: Discrete scenario trees with assigned probabilities
- Output: A delivery date with a quantified confidence interval
On-Time In-Full (OTIF)
The ultimate customer-facing metric that validates CTP accuracy. OTIF measures the percentage of orders delivered with the complete quantity on the exact date promised. A failed CTP check—overpromising capacity—directly degrades this score.
- Calculation: (Orders delivered on time AND in full) / (Total orders)
- Penalty: Both late and incomplete shipments count as failures
- Target: World-class operations aim for >98.5%
Component Commonality
A design strategy that makes CTP checks more flexible. By using identical components across multiple end products, the system can pool capacity and material constraints. A CTP engine can re-allocate a shared sub-assembly from a lower-priority order to fulfill a high-priority one.
- Benefit: Reduces the number of unique constraints
- Risk Pooling: Aggregated demand variability is lower
- CTP Impact: Increases the 'capable' part of the promise

About the author
Prasad Kumkar
CEO & MD, Inference Systems
Prasad Kumkar is the CEO & MD of Inference Systems and writes about AI systems architecture, LLM infrastructure, model serving, evaluation, and production deployment. Over 5+ years, he has worked across computer vision models, L5 autonomous vehicle systems, and LLM research, with a focus on taking complex AI ideas into real-world engineering systems.
His work and writing cover AI systems, large language models, AI agents, multimodal systems, autonomous systems, inference optimization, RAG, evaluation, and production AI engineering.
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