The R&D department of a Markstrat company cannot keep track in its records of more than 20 Sonite R&D projects plus 20 Vodite R&D projects. If a team launches more that 20 projects in a given market, the oldest ones will be lost and replaced by the newer ones.
Imagine a cabinet with limited shelf space where the R&D team can only store 20 projects in total. A Markstrat company has only two such cabinets, one for Sonites and one for Vodites. This is not a big issue as old projects are usually irrelevant to new customer expectations