The following appeared in a memo from a vice president of Quiot Manufacturing

The following appeared in a memo from a vice president of Quiot Manufacturing. “During the past year, Quiot Manufacturing had 30 percent more on-the-job accidents than at the nearby Panoply Industries plant, where the work shifts are one hour shorter than ours.”

To start with, there is a survey showing that Quiot Manufacturing had 30 percent more on-the-job accidents than at Panoply Industries plant. Based on this, the author readily assumes that the possibility of the accidents at Quiot is higher than that at Panoply. However, in some cases, the possibility is not equal to the times of on-the-job accidents. For example, if the number of workers at Panoply is far smaller than that at Quiot, it is not surprising to see that only a few on-the-job accidents occur, but it does not mean this kind of accident hardly happens. Moreover, although the length of work shifts is much longer, the unstated assumption that the workers at Quiot are easier to feel tired and sleepy is unreasonable. We are not informed whether or not the workers at the two plants only need to be present on one work shift. If workers at Panoply are forced to work more times a day than at Quiot, they will be more likely to feel exhausted and the assumption will therefore be weakened.

Even if the assumptions mentioned above remain tenable, we cannot safely assume that the general experience from experts can be directly applied to Quiot Manufacturing. In other words, there may be some particular factors causing on-the-job accidents. If the machines are of high risk to handle due to complicated and sharp components or the workers lack training and experience, either of the two cases, rather than workers’ fatigue and sleepy feeling, will become a more significant reason. In such circumstances, this assumption is undermined and the author’s recommendation is therefore unreliable.

Granted that the casual relationship from expert experience is advisable, we should still examine the reasoning of the final recommendation. One assumption is that shortening work shifts will enable workers to get adequate amounts of sleep. However, it may be helpless. If most work shifts at Quiot are late at night and early in the morning, this means workers have to adjust their body clock to work, decreased working time will be less helpful for them to have a better rest. In addition, the author also easily assumes that a reduction in on-the-job accidents will have a positive effect on Quiot Manufacturing’s productivity. But this assumption is questionable because there is no information about whether machines’ operation can be influenced by the accidents. If the machines at Quiot can still work after an occurrence of that accident, and other workers can take over previous tasks immediately, productivity cannot boost only by decreasing the number of accidents.