Picture a small metal fabrication shop. An order comes in. The foreman walks to the storage room, checks the shelves, scribbles a list of missing materials on a notepad, and picks up the phone to call a supplier. Meanwhile, the bookkeeper is recording invoices in a separate ledger, and the sales manager is tracking orders in a paper folder on his desk. Nobody talks to each other in time. Deliveries are late, customers are unhappy, and the owner cannot tell at any given moment whether the business is making money. This scene plays out in many manufacturing firms. Two types of computer programs exist to solve different parts of this problem: one is called MRP, the other is ERP. They are not the same thing, and choosing the wrong one is an expensive mistake.
MRP stands for Material Requirements Planning. The job of an MRP program is to answer one specific question: given the orders I have right now, what materials do I need, in what quantities, and by what date? The program takes three inputs — the bill of materials for each product (which parts go into what), current inventory levels, and the production schedule — and calculates what is missing. It then tells you: ‘You need to order two hundred bolts, fifteen metres of steel sheet, and eight kilograms of paint by Thursday.’ That is it. MRP is a factory-floor tool. It does not handle accounting, it does not manage customer invoices, and it does not track sales performance. Its entire purpose is to keep the production line from running out of raw materials.
ERP, which stands for Enterprise Resource Planning, is a far broader type of program. It connects all the departments of a company — accounting, purchasing, sales, inventory, and production — inside a single database. When the sales team enters a new order, that information flows automatically to the warehouse and to accounting at the same time. When a payment goes out to a supplier, the accounting record updates without anyone entering the same number twice. In short, ERP gives the owner a single screen that reflects the real state of the entire business. MRP is actually one piece inside a full ERP system; most ERP programs sold to manufacturers include a production and materials planning module that performs MRP functions.
What does this difference mean in practice? A workshop that only manufactures goods and still handles finance and sales through a separate accounting program or through manual records may find MRP sufficient for now. If the product recipes are complex, orders arrive frequently, and raw material shortages regularly delay production, an MRP program brings real order to the floor. Waste drops. Late deliveries become less common. The production manager opens the computer in the morning and finds the week’s schedule alongside a clear list of what needs to be ordered. That single change can save hours every week.
ERP becomes relevant when the business grows past a certain point and information stops flowing between departments. When you need to call the salesperson to get revenue figures, wait for the bookkeeper to calculate costs, or walk down to the warehouse to check stock levels, you are losing time that a connected system would recover. With ERP, a transaction entered once is visible everywhere. The accounting module updates receivables the moment an invoice is issued. The inventory module calculates costs when goods leave the warehouse. The production module tracks raw material consumption as it happens. For a company with separate sales, production, and finance operations — typically a firm with more than ten to fifteen staff carrying distinct responsibilities — this kind of integration is not a luxury; it is what makes reliable management possible.
A honest word about the difficulties, though. Neither system installs itself. An MRP program requires that every bill of materials be entered correctly, that stock counts be kept accurate, and that order data be updated consistently. If the data going in is wrong, the output is wrong — this is the most basic truth of any business software. ERP is harder still. Implementation takes months. Staff need time to learn the new workflows. During that learning period, production and sales cannot stop. Many companies buy ERP software, start the setup process, and end up using only the accounting module because the rest of the configuration was never completed. This is not a technology failure; it is what happens when a company purchases the software before mapping its own processes on paper first.
Before you make a decision, ask yourself three questions. First, is your core problem confined to the production floor — materials running out, production schedules slipping — or does the problem extend to disconnected information across sales, finance, and operations? Second, does your current accounting program cover finance well enough, or do you find yourself re-entering the same numbers in multiple places? Third, how many people are involved in running the business day to day, and do they need to share live information with each other? If production planning is the only pain point and the rest of the business runs acceptably, start with MRP — it is cheaper, faster to implement, and focused on the problem at hand. If the business has outgrown its current tools across the board, plan for ERP from the start. Either way, write down your own processes before you talk to any software vendor.
This article was originally written in Turkish by Gökhan MERCANOĞLU on April 17, 2000 and has been automatically translated into English and other languages using machine translation.