Business Central Costing for Manufacturing

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After 15 years implementing Business Central and NAV (and 30 years in ERP overall) in factories across Greece, UK and Europe, I can tell you one thing for sure: costing is where most manufacturing implementations succeed or fail.

If you set up costing properly, your managers get clear numbers, finance is happy, and variances actually help you improve. If you do it wrong, you will have big headaches every month-end.

This guide is written for people who work with manufacturing in Business Central every day: planners, production managers, and consultants.

1) Costing Basics in Business Central

Business Central has two main worlds in costing:

• Item Costing Methods: Standard, FIFO, Average, Specific
• Capacity Costs: Coming from Work Centers and Machine Centers (labor + machines)

My recommendation: For most discrete and repetitive manufacturing, use Standard Costing. It gives you clear variances and is much easier to control. For process or very simple environments, Average or FIFO can also work.

2) The Main Players You Need to Set Up

Work Centers & Machine Centers

This is where you define your real production costs.

On every Work Center you should set:

• Direct Unit Cost (e.g. 35€ per hour)
• Indirect Cost % (e.g. 20% for electricity, supervision)
• Overhead Rate (optional fixed amount per hour)

Machine Centers can have their own rates if they are more expensive.

Items

• Choose Standard costing for manufactured items
• Maintain Standard Cost using the Standard Cost Worksheet
• Set correct Posting Groups so costs go to the right G/L accounts

BOMs and Routings

• Production BOM = materials
• Routing = operations + times (Setup + Run time)

The combination of both gives you the full standard cost of the finished item.

3) Minimum Viable Setup (Step by Step)

1. Create proper G/L accounts (WIP Material, WIP Capacity, Finished Goods, Material Variance, Capacity Variance, etc.)
2. Set up Inventory Posting Setup and General Posting Setup correctly
3. Create Work Centers and Machine Centers with realistic rates
4. Set Items to Standard Costing
5. Build certified Production BOMs and Routings with good times
6. Run Standard Cost Worksheet → Suggest & Implement new costs
7. Test with one small production order

Do these things well and you already have 80% of good costing.

4) How Costs Actually Flow

When you release a production order and start posting:

• Consumption of components → material cost goes to WIP
• Output + Time posted → capacity cost (from Work Center rates) goes to WIP
• When you Finish the order → WIP moves to Finished Goods inventory and variances are calculated

Two very important jobs you must run every month:

• Adjust Cost – Item Entries
• Post Inventory Cost to G/L

Never forget these two. Many companies forget and then wonder why their numbers are wrong.

5) Day-to-Day Operations

Consumption Posting

You can use Backward flushing (automatic) for simple items, but for expensive materials I prefer Manual or Pick+Backward so you see real usage.

Output Posting

Always try to post actual time if possible. This is how you get good capacity variances.

Subcontracting

I usually create a Subcontracting Work Center. Link Purchase Order to the production order operation. This way the vendor cost comes automatically into the production order.

Rework

Create special operation or separate Work Center with higher rate. This way you can see the real cost of quality problems.

6) Month-End Close: My Practical Checklist

• Post or reverse all pending Consumption and Output journals
• Run Adjust Cost – Item Entries
• Run Post Inventory Cost to G/L
• Check WIP on open production orders
• Review variances (Production Order → Statistics)
• Explain big variances with production team
• Archive reports

Do this every month and you will sleep much better.

7) Understanding Variances

• Material Variance → wrong BOM, bad yield, or purchase price different from standard
• Capacity Variance → posted more or less time than routing says
• Overhead Variance → volume or rate issues

Variances are not bad. They are your best friend. They show you exactly where you lose money.

8) Good Practices from the Field

• Keep routing times realistic. If they are fantasy, your variances will also be fantasy.
• Review and update Standard Costs at least twice per year.
• Use Dimensions (Department/Cost Center) on Work Centers. This helps you see cost by production line.
• Train operators to post time properly. Bad time posting = bad costing.
• For high volume items, Backward flushing is fine. For expensive or critical items, use Manual.

9) Common Problems & How to Fix Them

• Zero capacity cost → You forgot to put Direct Unit Cost on Work Center
• Huge variances every month → Routing times or BOMs are outdated
• WIP not clearing → You didn’t Finish the production order properly
• Wrong G/L accounts → Check Inventory Posting Setup again

10) Quick Reference Cheat Sheet

Work Center Card

Direct Unit Cost | Indirect Cost % | Overhead Rate | Calendar | Default Dimension

Routing Line

Work/Machine Center | Setup Time | Run Time | Lot Size | Scrap %

Item Card

Costing Method = Standard | Standard Cost | Item Posting Group | Flushing Method

This guide should give you a solid practical understanding of costing in Business Central.

Costing is not only about numbers. It is about making your factory better. When you see clear variances and understand them, you can make real improvements.

If you have specific questions about your setup (especially in Greek factories), feel free to contact me.