If an article has a successor, it can be helpful to enter a successor article number in the article master.

On the one hand to support the sales department when they enter the discontinued item in the order to know what the successor is.

On the other hand it can be helpful for disposition programs to have this info, so that they can use sales figures from the predecessor article for the forecast.

The field and table substitute article is not the same, because there can be several articles in question that can be used as a substitute.