Wastes (muda) have all been caused by long production lead time and high levels of inventory. Both of these problems are related directly to each other and if the lead time excels, there is also a lot of inventory built up as well. You’ll understand better if you see the picture of iceberg. It is not an overstatement to say that almost all the costs of a company are hidden behind the problem of these both. Conversely, it can be said that reducing both is the best method of reduction of fix costs and variable costs.