Rough-Cut Capacity Planning (RCCP): A Quick Guide for Manufacturers

Before you dive into detailed scheduling, you need to know whether your production plan is even feasible. That is the job of rough-cut capacity planning (RCCP) — a fast, high-level check that compares your master production schedule against the capacity of your most critical resources.

RCCP does not tell you what to run on which machine at 2:00 PM on Tuesday. It tells you whether Tuesday's week is even achievable given your equipment and labor. Think of it as the feasibility test that prevents you from building a detailed schedule on a foundation of impossibility.

At User Solutions, we position RCCP as the first checkpoint in a planning process that ultimately leads to finite capacity scheduling — and we have helped hundreds of manufacturers structure this progression effectively.

Where RCCP Fits in the Planning Process

RCCP sits between the master production schedule and detailed material and capacity planning:

1. Sales and Operations Planning sets aggregate production targets
2. Master Production Schedule (MPS) specifies products, quantities, and timing
3. Rough-Cut Capacity Planning (RCCP) validates MPS feasibility against key resources
4. MRP explodes bills of materials and generates detailed work orders
5. Capacity Requirements Planning (CRP) validates MRP output against all work centers
6. Finite Capacity Scheduling creates executable shop floor schedules

The critical insight is that RCCP happens before MRP runs. If RCCP reveals that the master schedule is infeasible, you adjust the MPS before MRP generates hundreds of work orders that cannot be executed. This saves enormous rework downstream.

How RCCP Works

The Capacity Bill Method

The most common RCCP approach uses capacity bills — simplified resource profiles that estimate how much of each key resource one unit of each product requires.

For example, Product A requires:

• 2.5 hours of CNC machining per unit
• 1.0 hours of welding per unit
• 0.5 hours of assembly per unit

If the MPS calls for 40 units of Product A in week 22, the RCCP demand is:

Repeat for every product in the MPS, sum by resource, and compare against available capacity.

The Resource Profile Method

The resource profile method adds time-phasing by distributing a product's capacity requirements across multiple periods based on historical lead time patterns. If Product A has a 3-week manufacturing lead time and CNC machining occurs primarily in week 1, the 100 hours of CNC demand for a week 22 completion are loaded in week 20.

This provides a more accurate picture of when demand hits each resource, not just the total.

The Overall Factors Method

The simplest RCCP approach uses a single conversion factor: total labor hours per product multiplied by a historical ratio for each resource. This is less accurate but useful when detailed capacity bills are not available.

Resource Demand = Total Direct Hours x Resource Historical Percentage

If Product A requires 5 total direct hours and CNC machining historically consumes 50% of total hours:

CNC Demand per unit = 5 x 0.50 = 2.5 hours (same result as the capacity bill, but derived differently)

RCCP Formulas

Demand Calculation

Resource Demand (period) = Sum of (Capacity Bill Factor x MPS Quantity) for all products in the period

Capacity Availability

Available Capacity (period) = Number of Resources x Hours per Shift x Shifts per Day x Days in Period x Efficiency Factor

Load Ratio

Load Ratio = Resource Demand / Available Capacity

• Ratio < 0.85: Capacity surplus — consider reducing shifts or redeploying
• Ratio 0.85-1.00: Healthy range for key resources
• Ratio > 1.00: Overloaded — MPS is infeasible without corrective action

Capacity Gap

Capacity Gap (hours) = Resource Demand - Available Capacity

A positive gap means more hours are needed than available. Express as overtime hours required, additional shifts needed, or units that must be outsourced or deferred.

Key Resources: Focus on What Matters

RCCP deliberately limits its scope to key resources — the 3-5 work centers that most frequently constrain production. These typically include:

• Your bottleneck machine or work center
• Any resource with historically high utilization (above 80%)
• Resources with long changeover times that limit flexibility
• Shared resources that serve multiple product families
• Resources with specialized labor requirements

You do not need to check every work center at the RCCP level. If a resource runs at 50% utilization and has never been a constraint, including it in RCCP adds computation without insight. Save the comprehensive check for CRP.

Interpreting RCCP Results

Scenario: Balanced Plan

This MPS is feasible. Key resources are loaded in the healthy range. Assembly has surplus capacity, which is acceptable for a non-constraint.

Scenario: Overloaded Plan

CNC machining is 21% overloaded and welding is 8% overloaded. The MPS as written cannot be executed. Options:

1. Reduce the MPS: Defer lower-priority orders to week 23
2. Add capacity: Authorize overtime at CNC machining (25 hours needed) and welding (4 hours needed)
3. Rebalance: Move some CNC work to alternative machines if capable
4. Outsource: Send overflow machining to a subcontractor

The key is that you make these decisions before MRP runs — not after 200 work orders have been generated and released to the shop floor.

RCCP Best Practices

Keep It Simple

RCCP succeeds because of its simplicity. Do not try to make it as detailed as CRP. Focus on 3-5 key resources, use weekly time buckets, and accept that the results are approximate. An 85% accurate quick answer is more valuable than a 99% accurate answer that takes two weeks.

Validate Capacity Bills Quarterly

The accuracy of RCCP depends on the accuracy of your capacity bills. As product designs change, new equipment is added, or process improvements alter cycle times, capacity bills drift from reality. Review and update them quarterly.

Use RCCP as a Communication Tool

RCCP charts are excellent for S&OP meetings and cross-functional discussions. A simple bar chart showing demand versus capacity by week communicates the manufacturing reality to sales, finance, and executive leadership in a way that detailed scheduling data cannot.

Link RCCP to Financial Decisions

When RCCP shows persistent overload at a key resource — not just one week, but a 6-12 month trend — that is the data you need to justify capital expenditure. Conversely, when a resource shows chronic underutilization, RCCP provides the evidence for redeployment or divestment.

From RCCP to Detailed Scheduling

RCCP is step one. Once you have validated that the master schedule is feasible at the aggregate level, the next steps are:

1. Run MRP to generate detailed work orders and material requirements
2. Run CRP to validate detailed capacity at all work centers
3. Apply finite capacity scheduling to create an executable, sequenced production plan

Each step adds detail and precision. RCCP catches the big problems early. CRP catches the work-center-level issues. Finite capacity scheduling resolves everything into a time-sequenced plan your shop floor can execute.

RMDB handles the entire progression — from aggregate capacity analysis to daily finite scheduling — in a single integrated platform that layers on top of your existing ERP system.

The Bottom Line

Rough-cut capacity planning is your early warning system. It takes five minutes to run, requires minimal data, and catches infeasible production plans before they generate hundreds of work orders that cannot be executed. Every manufacturer running a master production schedule should perform RCCP — and the ones who do consistently avoid the fire drills that plague those who skip it.

Ready to validate your production plan? Schedule a demo of RMDB and see how integrated capacity planning — from rough-cut through finite scheduling — ensures your plans are feasible before they reach the shop floor.

Frequently Asked Questions

What is rough-cut capacity planning?

How does RCCP differ from CRP?

What data does RCCP need?

How often should RCCP be performed?

Can RCCP replace detailed capacity planning?