Standard accounting practice is to calculate a standard cost of goods sold, and apply it to the P&L to calculate gross margin. It is a system that has worked well, is well understood, and can be tuned by the use of variances.
It does however have the significant and usually unappreciated flaw of not reflecting the reality of the flow that occurs through a factory.
Standard Cost of Goods Sold is generally comprised of the direct material, and direct labour used to produce products, tuned to machine rates. Usually, the standards once set are in place for a lengthy period, with adjustments made for variances via labour and material variances on some sort of timetable, usually budget time. If the standard says that there will be $50 of material used, and you use $60, there is a variance that needs to be explained, and if not a one-off, included into the standard COGS. Similarly with labour direct costs. If the standard is that 100 units are produced during a shift, and you produce 110 units, you have a positive variance, your labour has been more productive than the standard indicated, your machines have run faster or for longer on the shift, so the standard should be adjusted.
The challenge however is to make the standards dynamic, so they do not hide inefficiency or the opportunity for productivity increases. In their most dynamic form, the standard COGS is dispensed with, and replaced by an actual cost of goods sold, which reflects the actual costs incurred.
Lean practitioners call this producing a value stream P&L.
Inventory purchased for resale or transformation can only be consumed in three ways:
- It passes through the manufacturing process and is sold
- It is scrapped during the manufacturing process, or after it as inventory becomes redundant for one reason or another
- It is stored as finished goods inventory to be sold or scrapped.
Every business I have ever seen has purchased materials for all three buckets. The improvement task is to reduce them all, done in a number of ways:
- Reduce scrap during manufacturing
- Increase the flow of manufacturing to reduce WIP
- Reduce the lead times for delivery of materials, introduce JIT deliveries.
- Manufacture to order, or as close as you can to it.
The impediment to this improvement is often the accounting process itself.
The balance sheet records inventory, no matter its type as an asset, and a reduction of inventory is a reduction of assets. This is not a great thing to an accountants eyes, and often contrary to the KPI’s of executives. The only benefit from an inventory reduction that can be seen on the balance sheet is the freeing up of cash, to be used more productively than being tied up in inventory to be sold or scrapped. However, you must look closely, as it is just a transfer from inventory to cash, that often goes unremarked.
I encourage all manufacturing businesses seeking factory efficiencies to move from a standard Cost of goods sold calculation to a dynamic one. It is an easy transformation to say, but is in my experience often a very hard one to ‘sell’ to financial management, and even harder to implement. However, the effort will be worthwhile, as it will deliver way more sensitive management of cost of goods sold calculation, and is one where ‘coalface’ staff can play a role that delivers satisfaction and engagement to them, contributing to improved productivity.
