The quality of your writing style should create a similar impression on the quality of the work being performed. When writing or re-writing an SOP you should include only details that clearly and concisely get the message of the task the operator should be completed without giving the operator any room for extra interpretation. The SOP should be dummy proof. An SOP is considered to be a form of technical writing which means that it should only convey facts, conveys directions, instructions, or explanations in simplified complex ideas with concise language. Also, keep in mind the audience you are writing.
There are 2 tests on Microsoft Word that I recommend that you use to determine the readability of your SOP; Flesch Reading Ease and Flesh-Kincaid Grade Level. These tests are inversely related, i.e. Flesh Reading Ease score is high, the Flesch Kincaid Level Score is low. This is a calculation based on the average number of syllables per word and words per sentence. The Flesh Reading Ease is a scale from 10-100 and higher the score the easier it is to read and understand. Flesch-Kincaid Grade level score analyzes and rates text on a US Grade-School level. It is based on average numbers of syllables per words or words per sentence. When writing your SOP aim for your readability score to be 80 and above and grade level to be around 10th grade.
Most of the posts above state that the SOP should be a very detailed document, and I agree with that as well, but I also like the comments made about being concise. There is a difference between being detailed and concise vs. detailed and redundant. I would also like to add to this conversation by discussing the correlation between how detailed an SOP is vs. how often it needs to be updated/revised. I think that the more detail that is included in the SOP will also result in having to update the procedure more often, because every little change to the procedure will require an update to the SOP. This is not necessarily a bad thing, but I think companies should make sure they account for this and have the appropriate resources to handle all of the SOP updates.
