Manufacturing & MRP module

From ERPEDIA, the independent ERP knowledge base

The manufacturing module (often called Production Planning or MRP) manages the entire production process. It ensures that raw materials, capacity, and resources are available to meet demand. It generates production orders, tracks shop floor activity, and calculates product costs.

1. Bill of materials (BOM)

The BOM is a complete list of raw materials, sub‑assemblies, and quantities needed to produce a finished product. It can be multi‑level (e.g., a bicycle includes a frame sub‑assembly, which itself requires tubes and welding).

BOM for "Desk Lamp" Base (plastic) – 1 pc Bulb (LED) – 1 pc Wiring kit – 1 set Wire – 2m Plug – 1 pc Switch – 1 pc

2. Routings & work centres

Routing defines the sequence of operations (cut, drill, assemble) to make a product. Each operation is assigned to a work centre (machine, assembly line, or skilled worker). The routing provides standard times for scheduling and costing.

3. Material requirements planning (MRP)

MRP is the engine that calculates what materials are needed, in what quantities, and when. It uses:

  • Sales forecasts / actual orders (from demand management)
  • BOMs (explosion)
  • Inventory on‑hand & on‑order
  • Lead times

MRP generates planned orders for production and purchase requisitions.

MRP logic: Gross requirements – on‑hand – scheduled receipts = net requirements. Net requirements are time‑phased to create order proposals.

4. Production orders

A production order (or manufacturing order) authorises shop floor execution. It contains:

  • Item to produce, quantity, due date
  • BOM and routing
  • Material reservations
  • Status (planned, released, in progress, completed)

As work is done, materials are consumed and labour/machine time recorded.

5. Capacity planning

Capacity planning checks whether work centres have enough capacity to execute the planned production. Finite scheduling sequences jobs based on available hours. Alerts identify overloads, allowing adjustments (overtime, subcontracting).

6. Shop floor control

Shop floor control tracks real‑time progress: operations started/completed, downtime, scrap, and labour reporting. Barcode scanning or IIoT devices feed data back to ERP, enabling WIP tracking and performance analysis.

7. Production costing

ERP calculates actual vs standard costs for each production order:

  • Material cost: Actual consumption × standard price (or actual).
  • Labour cost: Actual hours × labour rate.
  • Overhead: Allocated based on machine hours or labour.

Variances are posted to the general ledger for management review.

8. From MRP II to ERP

Manufacturing was the historical core of ERP. MRP II (Manufacturing Resource Planning) added capacity, finance, and simulation. Modern ERP manufacturing modules integrate with sales (demand), procurement, inventory, and finance – providing a complete picture.

ConceptRole in manufacturing
MPS (Master Production Schedule)What finished products to make and when
RCCP (Rough‑Cut Capacity Planning)High‑level capacity check
CRP (Capacity Requirements Planning)Detailed capacity check for work centres
Production order costingCollect actual costs, compare to standard

Key Takeaways

  • Manufacturing module manages the entire production lifecycle – from BOM to finished goods.
  • MRP calculates material needs based on demand, inventory, and lead times.
  • Production orders control execution and capture actual costs.
  • Capacity planning ensures resources are available.
  • Integration with procurement, inventory, and finance makes manufacturing efficient.

What is a phantom BOM? A BOM for a sub‑assembly that is consumed immediately in the next production step – it never goes to stock.

Can ERP handle process manufacturing (food, chemicals)? Yes, with features like co‑products, by‑products, potency, and shelf‑life management.

What is backward vs forward scheduling? Backward scheduling starts from due date and calculates start date; forward scheduling starts as early as possible.

Continue Reading in ERPEDIA

ERPEDIA is maintained by Professionals Lobby as an independent ERP knowledge initiative focused on reducing ERP implementation risk in the UAE and GCC.
For structured, vendor‑neutral ERP advisory → Speak with an independent ERP advisor.