Material Requirements Planning (MRP) is the backbone of efficient inventory management and production planning for manufacturing companies. In today’s competitive manufacturing sector, where customer demand, production processes, and inventory management are key factors for success, MRP systems have become indispensable. This article will delve into the intricacies of MRP, explaining how it works, the distinctions between MRP I and MRP II (Manufacturing Resource Planning), implementation steps, pros and cons, and the differences between MRP and ERP systems. We’ll also address frequently asked questions related to MRP, providing insights into how this computerized planning system optimizes material planning, production schedules, and resource utilization.

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What is Material Requirements Planning (MRP)?

Material Requirements Planning (MRP) is a computerized planning system that plays a pivotal role in materials and resource planning for manufacturing. It is used by manufacturing companies to ensure efficient allocation of resources to meet demand, streamline production processes, and minimize operational costs. MRP aids organizations in various sectors in optimizing their supply chain operations by determining the necessary materials, their timing, and quantities to meet future production demands accurately.

Read more: Production scheduling in manufacturing

How Material Requirements Planning (MRP) System Works

MRP systems are a critical component of inventory management and other production cycle planning. These systems utilize a combination of components, including the Bill of Materials (BOM), Master Production Schedule (MPS), and Inventory Status File (ISF), to determine the materials required for each production cycle and the timing of these requirements. The aim is to ensure that materials are available when needed, avoiding overstocking or shortages that can disrupt production schedules.

Here are the input data into MRP system:

  • Item Name or Nomenclature: The finished good title, sometimes called Level “0” on BOM.
  • Master Production Schedule (MPS): How much is required to meet demand? When is it needed?
  • Shelf life of stored materials.
  • Inventory Status File (ISF): Materials available that are in stock and materials on order from suppliers.
  • Bills of materials (BOM): Details of materials and components required to make each product.
  • Planning data: Restraints and directions like routing, labor and machine standards, quality and testing standards, and lot sizing techniques.

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Read more: The importance of production management in manufacturing

MRP I and MRP II: Differences Mapped

MRP I: Material Requirements Planning

MRP I primarily focuses on the raw materials, planning schedule production, and inventory management. It employs the Bill of Materials (BOM) and Master Production Schedule (MPS) to calculate the quantities and timing of raw materials and components needed for production.

What is MRP II? Manufacturing Resource Planning

MRP II is an extended version of MRP I, often referred to as Manufacturing Resource Planning. It offers a more holistic approach, integrating materials planning with other aspects of manufacturing, such as capacity planning, production scheduling, and financial management. MRP II provides a comprehensive view of the entire manufacturing process, aligning production capabilities with market demands and financial goals.

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Implementing MRP systems: Steps and Processes

The implementation of MRP systems involves several key steps:

  • Assessment: Evaluate existing processes, technology, and data accuracy to identify areas in need of improvement.
  • Selection: Choose the appropriate MRP software solution that aligns with your business needs and goals.
  • Data Preparation: Ensure data accuracy and currency, as MRP relies heavily on accurate data.
  • Training: Provide training to your team to effectively utilize the MRP system.
  • Testing and Piloting: Run tests and pilot programs to ensure the system functions smoothly and meets your requirements.
  • Integration: Seamlessly integrate MRP into existing processes and systems.
  • Continuous Improvement: Regularly review and enhance the system to adapt to changing business conditions and demands.

Advantages and Disadvantages of MRP


  • Enhanced Efficiency: MRP systems bring efficiency gains by reducing manual planning efforts and optimizing resource utilization.
  • Material availability: Materials and components are available when needed
  • Lower Inventory Costs: They minimize inventory levels, reducing holding costs.
  • Improved Customer Service: Timely production based on MRP schedules ensures on-time deliveries, enhancing customer satisfaction.


  • Complex Implementation: Implementing MRP systems can be time-consuming and resource-intensive.
  • Data Accuracy: Accuracy is crucial, as incorrect data can lead to inefficiencies.
  • Costs: Initial setup and ongoing maintenance costs can be significant.

MRP vs. ERP: The difference between MRP and ERP systems

Enterprise resource planning (ERP) is an extension of MRP systems.

MRP systems primarily focus on production and materials planning, while ERP systems are broader in scope, encompassing various business functions, including finance, human resources, sales order and customer relationship management.

MRP is specialized in optimizing manufacturing processes, while ERP provides a comprehensive view of an organization’s entire operations.

ERP systems offer several benefits, including enhanced efficiency, integrated information, customized reports, and high-quality of customer service.

MRP Software

The primary objective of MRP software is to prevent overstocking or shortages of critical components, ensuring that manufacturing processes run smoothly and that products are produced on time to meet customer demand. It is a vital tool in the manufacturing sector, contributing to improved customer satisfaction and cost savings through efficient supply planning and inventory control.

Read more: Manufacturing project management: A roadmap to efficiency and success


1. MRP Inputs

MRP systems rely on specific data inputs, including the Bill of Materials (BOM), Master Production Schedule (MPS), Inventory Status File (ISF), lead times, order policies, and other relevant data to perform accurate planning and production process.

2. MRP Outputs

MRP systems generate a range of outputs, such as material purchase orders, production schedules, inventory status reports, customer orders and performance and planning reports that aid in decision-making.

Businesses can use Just-in-time (JIT) production, scheduling production based on material availability. It minimizes inventory levels and maximize manufacturing efficiency at optimal cost.

3. How do MRP systems bring benefits to companies?

MRP systems offer numerous benefits in business processes, including efficient resource allocation, cost reduction through inventory control, improved production scheduling, more production capacity and better customer service.

By automating and optimizing processes, MRP systems enable companies to operate more efficiently and profitably.

Additional Reading: History of MRP

The history of Material Requirements Planning (MRP) can be traced back to the mid-20th century, and it has evolved significantly over the years. Here’s a brief overview of the key developments in the history of MRP:

Post-World War II Manufacturing:

After World War II, the manufacturing industry experienced significant growth, leading to increased complexities in managing materials and production processes. Companies relied on manual methods for materials planning and inventory control.

Early Computer Systems:

In the 1950s and 1960s, as computers became more accessible, companies started to explore the use of computer systems for managing their production and inventory needs. These early computer systems laid the foundation for what would become MRP.

MRP I Emerges (1960s):

The concept of Material Requirements Planning (MRP) as we know it today began to take shape in the 1960s. Joseph Orlicky, often considered the “father of MRP,” played a significant role in its development. He introduced the idea of using computer systems to calculate the exact requirements for raw materials and components based on production schedules.

The Role of IBM:

IBM was one of the pioneers in developing and popularizing MRP systems. They created one of the early computer programs for MRP in the 1960s. This marked a significant step toward automation in manufacturing.

Evolution into MRP II (1980s):

In 1983, Oliver Wight developed MRP into MRP II, which expanded its scope beyond materials planning.

MRP II integrated various aspects of manufacturing, including capacity planning, the control system shop floor control, and financial management, providing a more comprehensive view of the manufacturing process.

Widespread Adoption:

With the advent of personal computers and the development of user-friendly MRP software in the 1980s and 1990s, MRP and MRP II became more accessible to a wide range of manufacturing companies. This led to widespread adoption across industries.

Integration with ERP (1990s):

In the late 1990s and early 2000s, MRP and MRP II systems became integrated into larger Enterprise Resource Planning (ERP) systems. This integration allowed businesses to manage not only their manufacturing processes but also other functions like finance, human resources, and customer relationship management.

Further Technological Advancements:

With the rise of the internet and cloud-based technology, modern MRP systems have become more sophisticated and user-friendly. They often include features such as real-time data, mobile access, and enhanced reporting and analytics.

Globalization and Supply Chain Complexity:

In the 21st century, globalization and increasingly complex supply chains have driven the need for more advanced MRP systems that can handle a full inventory requirements, wide range of production scenarios and adapt to changing market conditions.

Today, MRP remains a vital tool for manufacturing companies seeking to optimize their production processes, enhance resource utilization, and minimize operational costs. It continues to evolve alongside advancements in technology and the changing landscape of their manufacturing operations, playing a crucial role in helping businesses meet customer demand and maintain a competitive edge in their respective industries.


Material Requirements Planning (MRP) is a sophisticated system used by manufacturing companies to optimize production processes, enhance resource utilization, and minimize operational costs.

It comes in two forms, MRP I and MRP II, with the latter providing a more comprehensive approach to manufacturing resource planning. Implementing MRP systems can be complex, but the benefits of improved efficiency and reduced inventory costs make it a valuable investment for businesses. In the broader context, MRP differs from ERP, which integrates various business functions.

MRP systems play a crucial role in ensuring companies can meet customer demands and maintain a competitive edge in their respective industries.

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