The following appeared in a letter from the owner of the Sunnyside Towers apartment complex to its manager."One month ago, all the showerheads in the first three buildings of the Sunnyside Towers complex were modified to restrict maximum water flow to one

The owner of the complex, believes that changing the showerheads in three buildings of the complex decreased their costs and so this modification should be implemented in all buildings in order to get greater profit. Although, it seems, logically, acceptable, the author fails to present accurate evidence which are needed to evaluate the argument, effectively.

First, The author did not present any detailed statistics of decrease in water consumption. He/She only superficially, mentioned because they should spend money on water, thus, the change will decline their costs. But it is possible that the declined cost was result of other events, For example, relative organization, decreased water price or the maintenance costs was less in last month. So, an exact evidence of decrease in water consumption is needed to bolster the argument.

Also, as it is mentioned, there are some complaints about low pressure. As time goes by, this flaw can lead to the less popularity of complex between people to occupy in those buildings. If this happens, consequently, the apartments would remain empty and residents prefer to live in other complexes and areas. So the expected profit increase that author mentioned will not happen. Thus, It should be investigate accurately that whether the modification affect on popularity of the buildings or no. If so, it may even decrease their revenues.

The other evidence that should be prepared to made the argument more cogent is that, can this lower pressure impair the related equipment. For example lower water pressure cause more sediments remain in pipes and cause additional costs in order to repair them. In this case, it is possible that burdened costs outweigh the possible higher profit.

Also, The quality of new showerheads should be considered. They might be constructed from low quality materials or suffer from some technical problems that made owner replace them in shorter periods than ordinary showerheads which can leads to higher costs than profit for the authorities.

So, It can be seen that, author should wait for longer time from modification and present more strong evidences in order to decide that all the buildings shower should be changed with new one.