What is Infinite Capacity? Definition & Manufacturing Examples

What is Infinite Capacity?

Infinite capacity planning is a scheduling approach that assumes every resource can handle an unlimited amount of work. When loading jobs onto machines or work centers, the system does not check whether capacity actually exists. If 200 hours of work need to be done on a machine with only 80 available hours per week, infinite capacity planning loads all 200 hours and leaves it to the planner to figure out the overload.

This approach is common in traditional MRP systems and rough-cut capacity planning.

How Infinite Capacity Works in Manufacturing

In an infinite capacity system, the MRP engine calculates when each operation should occur based on lead time offsets and due dates, then assigns the work to the appropriate work center without checking if that work center is available. The result is a planned schedule that may show 300 percent loading on some resources and 20 percent on others.

After the initial load, the system typically generates a capacity requirements report showing the overloads. Planners then manually resolve these conflicts by moving work to earlier or later periods, authorizing overtime, outsourcing, or negotiating due date changes.

The obvious weakness is that the system generates plans that cannot be executed as written. The planner must do the hard work of creating a feasible schedule manually, often in spreadsheets or through trial and error. In shops with hundreds of open orders and dozens of work centers, this manual resolution process can consume hours every day and still miss conflicts.

Infinite capacity planning was designed for an era when computing power was limited and the goal was simply to calculate material requirements. For material planning — determining what to buy and when — infinite capacity works reasonably well. For detailed shop floor scheduling — determining which machine runs which job and when — it is fundamentally inadequate.

Infinite Capacity Example

A shop has 2 CNC machining centers available 80 hours per week each, for a total capacity of 160 hours. The MRP system generates the following plan for next week:

• Monday: 45 hours loaded (OK)
• Tuesday: 52 hours loaded (overload by 20 hours across both machines)
• Wednesday: 38 hours loaded (OK)
• Thursday: 60 hours loaded (overload by 28 hours)
• Friday: 25 hours loaded (underloaded)

Total weekly load: 220 hours against 160 hours of capacity — a 38 percent overload. The MRP system does not flag this during planning. The planner discovers the problem in a separate capacity report and spends 2 hours rearranging work manually. Some jobs get pushed to the following week, affecting downstream operations and potentially delivery dates.

With a finite capacity system, these overloads would never occur. The system would automatically sequence the 220 hours across available time slots, pushing excess work into the following week and flagging the impact on due dates immediately.

Why Infinite Capacity Matters for Production Scheduling

Understanding infinite capacity is important because it explains why many manufacturers struggle with on-time delivery despite having planning systems in place. If your MRP or ERP generates plans using infinite capacity logic, the schedule it produces is a wish list, not a commitment.

The solution is to layer finite capacity scheduling on top of your MRP system. Tools like Resource Manager DB (RMDB) take the orders from your MRP or ERP and schedule them against actual finite capacity, producing realistic schedules that the shop floor can execute. This eliminates the manual overload resolution that consumes planner time and produces the scheduling accuracy that drives on-time delivery above 95 percent.

Related Terms

• Finite Capacity — The opposite approach that respects actual resource limits and produces executable schedules
• Capacity Planning — The broader process of matching workload to resources at strategic, tactical, and operational levels
• Loading — The act of assigning work to resources, done with or without capacity constraints

Frequently Asked Questions

Learn more in our complete manufacturing glossary or production scheduling guide.