# Joint Products, By-Products & Co-Products — Concepts
In many process industries (oil refining, dairy, meat processing), a single common process yields multiple outputs. Costing depends on whether each output is treated as a joint product, by-product, or co-product.
## Process Flow Diagram
```
┌──→ Product A → Further Processing → Final Sale
Joint Input ──→ Common Process (Joint Costs)
└──→ Product B → Further Processing → Final Sale
↑
Split-Off Point
```
- Joint Costs = combined costs incurred up to the split-off point
- Split-Off Point = the stage at which joint products become separately identifiable
- Separate (Further) Processing Costs = costs incurred after split-off, traceable to individual products
## Definitions
### Joint Product
> When two or more products of equal importance are produced simultaneously from the same process and each has significant relative sales value, they are called Joint Products.
Examples: Milk, Cream, Yoghurt, Cheese (from dairy); Petrol, Diesel, Kerosene (from crude oil).
### By-Product
> When a product is recovered incidentally from the material used in production and it has very low realisable or usable value compared to the main product.
Example: Lemon oil from processing fruits; molasses from sugar refining.
### Co-Product
> Products that are contemporary to each other, but not necessarily produced from the same material or process.
## Quick Comparison
| Feature | Joint Product | By-Product | Co-Product |
|---|---|---|---|
| Source | Same process | Same process (incidental) | May be different processes |
| Value | Significant, comparable | Low compared to main | Comparable |
| Intent | Intended output | Incidental output | Intended output |