Managing Differences, The Central Challenge of Global Strategy by Pankaj Ghemawat, Harvard Business Review, March 2007. This article has mentioned some differences between manufacturing and services.

First, a person’s services usually can’t be stored.

Second, a person’s functionality can’t be summarized in the same standardized way as a part’s, with a serial number and a description of technical characteristics.

Third, in allocating people to teams, attention must be paid to personality and chemistry, which can make the team either more or less than the sum of its parts; not so with machines.

Fourth, for that reason and others (employee development, for instance), assignment durations and sequencing are additionally constrained.