Title: MRP vs MRP II: The Difference URL: https://zudoworks.com/answers/mrp-vs-mrp-ii/ Description: MRP vs MRP II in plain words: MRP plans materials from BOMs and demand; MRP II adds capacity, shop-floor control and finance. What it means for your shop. Updated: 2026-11-03 # MRP vs MRP II: what is the difference? MRP, material requirements planning, calculates what materials to make and buy, how many and when, from demand, bills of materials, stock and lead times. MRP II, manufacturing resource planning, extends that to the rest of production: capacity at work centres, shop-floor control, master scheduling and a link to costs and finance. ERP later extended MRP II across the whole business. By Arunkumar V, CTO · 03 November 2026 · 3 min read [Try ZMOS free](https://app.zudoworks.com/signup) [Book a 20-minute demo](https://zudoworks.com/contact/) - MRP II meaning - manufacturing resource planning - material requirements planning - MRP II vs ERP ## MRP: planning materials MRP answers one question: given what we must ship, what must we buy and make, and by when. It takes a master schedule of finished items, explodes it through multi-level BOMs, nets each component against stock on hand and open orders, and offsets by lead time. The output is planned purchase and work orders with release dates. Joseph Orlicky's 1975 book made the method standard, and the APICS MRP crusade of the 1970s spread it widely. MRP assumes capacity is infinite. It will happily plan 400 hours of work for a week in which you have 160. That gap is what MRP II set out to close. ## MRP II: planning the whole production system MRP II, a term associated with Oliver Wight in the 1980s, kept the MRP calculation and wrapped it in a closed loop. Rough-cut capacity planning checks the master schedule against work-centre hours. Capacity requirements planning checks the detailed plan. Shop-floor control reports what actually happened so the next run starts from reality. Standard costs, routings and work centres become master data, so the plan can be priced and compared with actuals. The second word changed from requirements to resource on purpose: the system plans people and machines, not only parts. MRP II is the direct ancestor of the manufacturing modules in current ERPs. ## Side by side The table sets out the main differences. Both are planning methods rather than products; the names survive mainly in textbooks and in the module lists of ERP vendors. When a vendor says MRP today, ask which column they mean, because the answer decides whether capacity and labour are planned or only materials. | Aspect | MRP | MRP II | | --- | --- | --- | | Plans | Materials only | Materials, capacity, schedule | | Capacity | Assumed infinite | Checked against work centres | | Feedback | None built in | Closed loop from shop floor | | Finance | Not linked | Costs and simulation linked | | Era | 1960s to 1970s | 1980s | ## What this means for a small shop now Nobody sells MRP II under that name any more; the functions live inside manufacturing ERPs. The distinction still matters when you evaluate software, because products differ in exactly the way MRP and MRP II did. Some plan materials well but know nothing about hours at a work centre. Others carry routings, work-centre rates and labour logging, so a plan can be checked against capacity and a job can be costed against the plan. For a 10 to 50 person shop the MRP II ideas that pay off first are routings with work centres, labour logged against jobs and a job cost that compares actual with expected. Full capacity planning can wait until the shop runs close to its limit. ## Where ZMOS fits ZMOS carries the MRP II master data a small shop needs: BOMs with revisions, scrap and cost roll-up, routings with work centres, labour logged at work-centre rates, and job costing that reports material at real issue cost plus labour per job and per unit when the job closes. Purchased parts are planned with reorder points per item. It is built for sheet-metal, machining and fabrication shops of 10 to 50 people. If you need finite capacity scheduling across many work centres, or a time-phased MRP run on deep BOMs, test those specifically in a demo before relying on it. [What ZMOS does](https://zudoworks.com/zmos/) - [routings and work centres](https://zudoworks.com/zmos/production-and-bom/) - [job costing in ZMOS](https://zudoworks.com/zmos/job-work-and-costing/) - [manufacturing guides](https://zudoworks.com/manufacturing/guides/) ## People also ask Short answers, each one complete on its own. ### Related answers - [What is the difference between ERP and MRP?](https://zudoworks.com/answers/erp-vs-mrp/) - [What is a manufacturing ERP?](https://zudoworks.com/answers/what-is-a-manufacturing-erp/) - [What is a routing and a work centre?](https://zudoworks.com/answers/what-is-a-routing-and-work-centre/) - [What is a bill of materials?](https://zudoworks.com/answers/what-is-a-bill-of-materials/) - [What is job costing in manufacturing?](https://zudoworks.com/answers/what-is-job-costing/) - [What is an immutable stock ledger?](https://zudoworks.com/answers/what-is-an-immutable-stock-ledger/) - [All 54 answers](https://zudoworks.com/answers/) ### Inside ZMOS [Zudo AI](https://zudoworks.com/zudo-ai/)[Stock ledger](https://zudoworks.com/zmos/stock-ledger/)[Low-code forms and rules](https://zudoworks.com/zmos/low-code/)[Barcode job cards](https://zudoworks.com/zmos/barcode-job-cards/)[Roles, audit log, API](https://zudoworks.com/zmos/roles-audit-api/)[Security](https://zudoworks.com/zmos/security/)[Free trial](https://zudoworks.com/zmos/free-trial/)[Why Zudo Works](https://zudoworks.com/why-zudo-works/) Is MRP II the same as ERP? No. MRP II covers manufacturing planning and its link to costs. ERP, a term Gartner coined in 1990, extended that integration to finance, sales, purchasing, HR and the rest of the business on one database. Every manufacturing ERP contains MRP II ideas. Does a small shop need capacity planning? Not at first. Most shops of 10 to 50 people know their bottleneck by sight. Capacity planning becomes useful when quoted delivery dates keep slipping and nobody can say which work centre is the constraint. Start with routings and labour logging, which capacity planning needs anyway. What is closed-loop MRP? An MRP run whose plan is checked against capacity and corrected with feedback from the shop floor and purchasing before it is executed. The loop is what MRP II added to plain MRP, so that the next plan starts from what actually happened rather than from the last plan. What is a master production schedule? The statement of which finished items will be built, in what quantity, in each period. MRP explodes it into component needs; MRP II checks it against rough-cut capacity. In a small shop it is often just the confirmed order book sorted by promised date.