And more like this.
“To reduce the dimensionality of the problem, administrators would often track the total tonnage of a few broad classes of steel tubes in the models, rather than using a more detailed classification scheme. While their models successfully balanced the tonnage of tubes for the broad categories (the output in tons of tube-producing factories matched the input requirements in tons of tube-consuming factories), there were constant surpluses of some specific types of tubes, and shortages of other specific types of tubes. In particular, since tonnage was used as a metric, tube-producing factories were overly incentivized to make easy-to-produce thick tubes. As a result, thin tubes were always in short supply.”
https://chris-said.io/2016/05/11/optimizing-things-in-the-ussr/