Production Tech Cards (Bill of Materials)
Keeping your bills of materials in Excel — and every material price change breaks all the calculations? A tech card in a spreadsheet goes stale instantly: raw material prices changed, norms were updated, but cost is still calculated the old way. There’s no link to real stock or production, formulas break, and a new card has to be rebuilt by hand every time.
A tech card (bill of materials) is the «recipe» of a product and the foundation of production accounting. In ERPJS you build a tech card once, and from then on it works on its own: it calculates material requirements, writes off raw materials and computes the actual cost of every order. Below — what a tech card is, how to build one and why it’s better kept out of Excel.
What is a product tech card (bill of materials)?
A product tech card is a document that describes which materials and in what sequence of operations a unit of product is made. Essentially it’s the product’s recipe: how much raw material is needed, which operations are performed, on what equipment and in what order.
A tech card is needed to produce consistently, plan raw material purchasing and calculate cost. Without it, production lives «in the head» of a foreman — and when they leave, the knowledge of how to make the product leaves with them.
What goes into a tech card? (structure)
A complete product tech card usually contains five blocks:
Materials and usage norms
A list of raw materials and components with the norm per unit of product — how much of each goes into one item.
Sequence of operations
Production stages in the right order: cutting, assembly, painting, packaging and so on.
Equipment and work centres
Which machine or station performs each operation. Useful for workshops with several work centres.
Time and labour norms
How long an operation takes — the basis for capacity planning and labour cost calculation.
The fifth block is standard cost: the sum of material value and labour per unit. That’s exactly what a tech card is built for — to know how much a product costs to make before production even starts.
How to build a tech card? (step by step)
You can build a product tech card in five steps:
- Define the final product and unit of measure — what exactly you make and how you measure it (piece, kilogram, metre).
- List materials and norms — all raw materials and components with quantity per unit of product.
- Define operations in sequence — from first to last, in the order the product is actually made.
- Link equipment and time — which machine performs the operation and how long it takes.
- Calculate cost — materials plus labour give the standard cost per unit.
We covered a step-by-step guide with an example in the article Tech Card: Why You Need One and How to Stop Keeping It in Excel.
Why keep a tech card in an accounting system rather than Excel?
In Excel a tech card is a static table, disconnected from real production. As soon as a material price changes, all cost calculations go stale and have to be rewritten by hand. There’s no link to stock: the system doesn’t know whether there’s enough raw material for an order. Formulas break, card versions get confused, and an error in a norm is easy to miss.
In an accounting system the tech card becomes a working tool, not just a document. It’s linked to a materials catalogue with current prices, to stock with balances and to production orders. A change in a raw material price instantly recalculates the cost of every product it goes into.
How do tech cards work in ERPJS?
In ERPJS a tech card (recipe) is created once, and the system then uses it automatically for every production order:
- Material requirement calculation. You create an order for the required quantity — the system multiplies the norms from the tech card and shows how much raw material is needed and whether there’s enough in stock.
- Automatic write-off and cost. At launch, materials are written off from stock by the norms, and on completion the system calculates the actual cost of finished goods.
- Multi-stage and equipment. The tech card defines the sequence of operations linked to equipment, supports semi-finished goods and even outsourcing of individual operations.
So a tech card in ERPJS isn’t a separate spreadsheet but part of a single cycle: recipe → order → stock → cost. How this works overall is described on the ERP for Manufacturing page and in the article Production accounting: how to automate from raw materials to finished goods.
A tech card in ERPJS is built once and works on its own: it calculates material requirements, writes off raw materials from stock and computes the actual cost of every order. A change in a material price instantly recalculates cost — with no manual re-working of spreadsheets.
Which manufacturers need tech cards?
Tech cards are needed by any manufacturer where a product is assembled from materials through a repeatable process:
- Furniture and woodworking
- Garment and textile
- Food and confectionery (recipes for dishes and semi-finished goods)
- Metalworking and assembly
- Advertising production and printing
- Windows, doors and structures
The more complex the product and the more materials it has, the more a tech card saves in time and money. How to calculate cost correctly from a tech card — in the article Cost of Goods: What to Count and What Not To.
Frequently asked questions
What is a product tech card in simple terms?
It’s the product’s recipe: a document describing which materials, in what quantity and in what sequence of operations a unit of product is made. A tech card is needed to produce consistently, plan purchasing and calculate cost.
What should a tech card include?
A list of materials with usage norms per unit, the sequence of operations, equipment for each operation, time and labour norms, and a standard cost calculation. This is the minimum set, which is enough for production accounting in a small or medium business.
How do you build a tech card?
Define the product and unit of measure, list all materials with norms per unit, set out the operations in sequence, link equipment and time, calculate the cost. In an accounting system this is done once, after which the card is used automatically for every order.
Why is a tech card in software better than Excel?
In software the tech card is linked to current material prices, stock and production orders. A change in a raw material price instantly recalculates cost, the system sees whether there are enough materials for an order, and writes them off automatically. In Excel all of this is done by hand and goes stale after the first price change.
Can you keep recipes for food production?
Yes. For a bakery, kitchen or semi-finished goods, the tech card works as a recipe: you set the composition of a dish, input norms and the output of finished product. The system calculates the cost per portion and the requirement of products per batch.
How long does it take to move from Excel to tech cards in the system?
Materials and finished products can be imported from a spreadsheet, and tech cards can be set up based on existing Excel recipes. For a small manufacturer the basic setup takes a few hours, after which the cards work automatically.