The following appeared in a report presented for discussion at a meeting of the directors of a company that manufactures parts for heavy machinery:“The falling revenues that the company is experiencing coincide with delays in manufacturing. These delays,

The author of the argument has failed to convince us that the replacement of the purchasing manager by a scientist will solve the problem of falling revenues. The argument, as it stands, is based on questionable assumptions and a faulty line of reasoning, a fact which renders it over-simplistic and unconvincing.

First of all, the author assumes that the reason behind the falling revenues is the delays in manufacturing. What he fails to examine, however, are other underlying causes of these delays such as poor distribution management, higher competition, lower demand, low quality of products, unsatisfied customers and so on. Furthermore, the author proceeds with a faulty line of reasoning by making another unsubstantiated assumption that for the manufacturing delays the poor planning in purchasing is responsible. Again, he/she does not consider other possible reasons such as lower worker productivity or mistakes in the manufacturing processes.

Second, although the author has failed to establish the real causes behind the problem of plunged revenues, he/she even proposes the solution of replacing the purchasing manager by a scientist from the research division. Nevertheless, the assumption here is the manager's inadequate knowledge of the properties of metals while other underlying causes could suggest a different course of action. As it is usually the case in manufacturing companies, critical decisions such as the supply of materials are not taken individually. Managers usually tend to consult scientists and engineers before taking action. The author implies that this is not the case without giving further explanations. In this case, the replacement of the manager by a scientist would have no effect.

In addition, we cannot be certain whether the aforementioned knowledge is a key aspect of the purchasing manager's job description and therefore he/she is the one to blame. Purchasing manager is mainly a managerial position, so the main characteristics of the job should be good managerial and organizational skills. Scientific knowledge, on the other hand, is important in the research and development department and, even if we assume that knowledge of metals in needed and that the scientist will cover this requisition, no one can guarantee that the scientist will not introduce other problems because due to his/her unfamiliarity in logistics.

To conclude, the argument based on unsubstantiated assumptions and poor evidence does not provide concrete support for its conclusion. If it had included the items discussed above, it would have been more thorough and convincing.