What is MRP software? A plain-English guide

MRP software — short for material requirements planning — is a system that calculates what materials you need to buy and what items you need to make, in what quantities, and by what dates, so that production never stalls for want of a component and your warehouse isn't drowning in excess stock.

It works from three inputs you already have: your bills of materials (BOMs), your current stock, and your orders. From those, it does the arithmetic that a production planner would otherwise do by hand in a spreadsheet — except continuously, across every product, and without missing a line.

What MRP software actually does

Imagine you assemble an electrical control panel. The finished panel has a BOM: an enclosure, a contactor, relays, wiring, terminal blocks, fasteners. Some of those are bought; some are sub-assemblies you build, which have BOMs of their own.

When a customer orders 50 panels for delivery in three weeks, MRP software:

• Multiplies out the BOM — 50 panels become 50 enclosures, 100 relays, 600 terminal blocks, and so on, down through every sub-assembly level.
• Checks what you already have — stock on the shelf, material already reserved for other orders, and purchase orders that are on the way.
• Calculates the shortfall — the net quantity of each item you still need to buy or produce.
• Works backwards from the delivery date — using supplier lead times and production durations to tell you when each purchase order must be placed and each work order must start.

The output is a plan: a list of suggested purchase orders and work orders, each with a quantity and a date. That's the whole job — and it's harder than it sounds to do reliably by hand once you have more than a handful of products or BOM levels.

MRP vs ERP vs inventory software

These three terms get used loosely, often by vendors. The honest distinctions:

Inventory software: tracking

Inventory software tells you what you have — quantities, locations, batches, valuations. It records movements but doesn't plan anything. If you only trade or distribute finished goods, this may be all you need. (Our inventory management software guide covers this category in depth.)

MRP: planning

MRP is a planning engine. It takes demand, BOMs and stock, and tells you what you need to do next — what to buy, what to make, when. Classic MRP doesn't handle invoicing, accounting or CRM; it's the brain that schedules materials and production.

ERP: the whole business

An ERP (enterprise resource planning) system wraps MRP together with purchasing, sales, inventory, accounting and more, so that the plan and the transactions live in one place. When MRP suggests a purchase order, you raise it in the same system; when goods arrive, stock and the supplier ledger update together.

In practice, most modern systems aimed at manufacturers — including Dravyaa — are ERPs with MRP-style planning inside. The label matters less than the question: does the system both track your stock and tell you what to buy and make next? If it only does the first, it's inventory software wearing an MRP badge.

How MRP works, step by step

Under the hood, every MRP run follows the same logic:

1. Gather demand. Confirmed sales orders, plus (optionally) a forecast for items you build to stock. This is the "master schedule" — what must be ready, and when.
2. Explode the BOMs. Each finished item is broken down into its components, level by level, until everything resolves to either a purchased item or a manufactured one. A multi-level BOM might explode three or four levels deep.
3. Net against supply. For each item, subtract free stock on hand and quantities already arriving on open purchase orders or being made on open work orders. What remains is the true net requirement.
4. Schedule backwards. Apply lead times: if a contactor takes ten days to arrive and assembly takes five, the system back-calculates the latest safe date to order and to start. Anything already late is flagged.
5. Suggest actions. The result is a set of recommended purchase orders (for bought items) and work orders (for made items), each with quantity and date, ready for a human to review and confirm.

MRP doesn't replace the planner's judgement — it replaces the planner's arithmetic. The decisions stay human; the calculations stop being error-prone.

Signs your SME has outgrown manual planning

Plenty of small manufacturers run perfectly well on a planner, a spreadsheet and a sharp memory. The trouble starts when complexity outgrows that setup. Familiar symptoms:

• Shortages discovered mid-production. A work order starts, and only then does someone realise a component is short — so the line stops, or the job is half-built and set aside.
• Excess raw material on some items, stockouts on others. Without netting demand against stock, buyers over-order "to be safe" on some materials while others slip through. Working capital sits as ₹ on shelves while the one part you need is missing.
• Expediting becomes routine. Air freight, premium courier charges, frantic calls to suppliers and part-load transport at panic rates — paying extra to fix planning gaps becomes a normal monthly expense.
• Everything depends on one person. The plan lives in one planner's spreadsheet and head. When they're on leave, purchasing guesses; when they resign, the system walks out the door with them.
• Promised dates are guesses. Sales commits to delivery dates without knowing whether materials can arrive in time, and the shop floor finds out the hard way.

If two or more of these feel familiar, the problem usually isn't effort — it's that the arithmetic has outgrown the spreadsheet.

What to look for in MRP software as an SME

Enterprise MRP suites exist, but they're priced and built for enterprises. For an Indian SME manufacturer, the practical checklist is shorter:

1. Multi-level BOMs

If your products contain sub-assemblies, the system must explode requirements through every level — not just the top one. Check this with your own deepest BOM before buying.

2. Live stock integration

MRP is only as good as the stock figures it nets against. Planning that reads from a separate, manually-updated stock file recreates the original problem. Stock, purchases and production should update one shared ledger in real time.

3. Reorder and shortage suggestions

The system should surface what to order and what's short before production starts — as a reviewable suggestion list, not a buried report you have to remember to run.

4. Simple enough for the shop floor

If creating a work order takes a training manual, supervisors will go back to the whiteboard within a month. Insist on a UI your team can use on day one, on a phone or a basic desktop.

5. GST compliance built in

In India, the purchase orders and invoices that MRP generates flow straight into GST returns and e-invoicing. A system that plans well but leaves compliance to a separate tool just moves the reconciliation problem to your accountant.

6. SME-grade pricing

Per-user enterprise licensing and six-month implementations don't fit a 20-person factory. Look for transparent subscription pricing in ₹ and an implementation measured in days or weeks, not quarters.

It's also worth checking the vendor understands your industry — the planning needs of a fabricator, a food processor and an electronics assembler differ more than brochures admit. (See the industries Dravyaa serves for examples.)

How Dravyaa approaches MRP

Dravyaa is an ERP for SME manufacturers, with MRP-style planning built into the production module rather than sold as a separate engine. The approach is deliberately simple:

• BOM-driven work orders. Define multi-level BOMs once; every work order knows exactly what materials it needs and reserves them.
• Live inventory underneath. Planning nets against the same real-time stock that inventory & warehouse transactions update, so suggestions are based on what's actually on the shelf.
• Shortage visibility before you start. Material shortfalls show up when the work order is planned — not when the line stops.
• AI-assisted reordering and forecasting. The AI assistant suggests reorder quantities and flags demand trends, so planning improves as your data accumulates.

If your team is still planning materials in spreadsheets, the fastest way to evaluate any MRP system — Dravyaa included — is to bring one real product with its full BOM and a live order, and watch the system plan it end to end.