MTS – make-to-stock is to produce just in case, mostly based on forecast of selling most demanded products. It happens when the market is not willing to wait until the order is manufactured and expects to buy “from stock”, hence the production starts without a firm order from a specific customer. There are also situations where there is not enough capacity – like in seasonality – and hence production has to start ahead of time.

 

Source: Oded Cohen and Jelena Fedurko, Theory of Constraints Fundamentals, 2012