Shall vs. Should in Quality Management System Documents
by Cynthia Blumenthal
When writing quality management system (QMS) documents that state requirements, most of us have used auxiliary verbs such as will, shall, may, might, should, and can.
An auxiliary verb “helps to form the voices, modes, and tenses of other verbs” (1). In the world of standards and regulations, the choice of an auxiliary verb in a sentence affects the intensity of a requirement.
Although the words, themselves, do not occupy much space in a sentence, misusing them can cause significant misunderstanding of a QMS document. Each sentence below delivers a distinct message, even when one appears to be essentially synonymous with another.
- Incoming materials are inspected before they are accepted in warehouse.
- Incoming materials may be inspected before they are accepted in warehouse.
- Incoming materials must be inspected before they are accepted in warehouse.
- Incoming materials shall be inspected before they are accepted in warehouse.
- Incoming materials should be inspected before they are accepted in warehouse.
- Incoming materials will be inspected before they are accepted in warehouse.
Among auxiliary verbs commonly used in QMS documents, the difference between shall and should is sometimes overlooked.
When used as an auxiliary verb, shall, according to Webster's Online Dictionary, “denotes a requirement that is mandatory whenever the criterion for conformance with the specification requires that there be no deviation” (2). This word implies obligation and is traditionally used by laws and regulations. For example, Chapter V of the Federal Food, Drug, and Cosmetic Act (FD&C Act), “Drugs and Devices,” begins with the following:
“A drug or device shall be deemed to be adulterated –” (3).
Similarly, the FDA’s regulations frequently use shall to indicate mandatory requirements. In CFR - Code of Federal Regulations Title 21, Part 803, the regulation for medical device reporting, the English reporting requirement states:
“All reports required in this part which are submitted in writing or electronic equivalent shall be submitted to FDA in English” (4).
On the other hand, should “denotes a guideline or recommendation whenever noncompliance with the specification is permissible.” When used as an auxiliary verb, it expresses “a conditional or contingent act or state … or moral obligation” (5).
The statement “Incoming materials shall be inspected before they are accepted in warehouse” is mandatory. All incoming materials must be inspected before they are accepted in warehouse. A deviation causes a noncompliance with the document.
In contrast, “Incoming materials should be inspected before they are accepted in warehouse” is a recommendation by the document writer. It allows the document users to make their own judgment calls.
In reality, the incoming materials will most likely be inspected before they are accepted. However, the document users at any time can make a deviation based on the specific situation, as long as the decision making is reasonable and logical. (Recall also that the word should does imply moral obligation.) Such deviation does not violate the document’s requirement.
Because of the built-in flexibility of the word, if the document writer intends to mandate a requirement, should is not an appropriate choice.
Update Your QMS Vocabulary
To use shall for a mandatory requirement delivers a clear, definite, and formal message. This formality, however, can also be a disadvantage.
Because of its limited popularity, shall may cause confusion and misunderstanding. Even the FDA has been attempting to modernize the format of its regulations to bring them closer to everyday English. Clause a) of the newer version of 21 CFR 803.13, “Do I need to submit reports in English?” reads:
“You must submit all written or electronic equivalent reports required by this part in English” (4).
Must, defined as “to be obligated” (6), is a good substitute for shall.
- "Definition: auxiliary," Webster's Online Dictionary.
- "Definition: shall," Webster's Online Dictionary.
- U.S. Food and Drug Administration, "SEC. 501. [21 USC § 351] Adulterated Drugs and Devices, Federal Food, Drug, and Cosmetic Act.
- U.S. Food and Drug Administration, 21 Code of Federal Regulations, part 803.13(a), 2005.
- "Definition: should," Webster's Online Dictionary.
- "Definition: must," Webster's Online Dictionary.
About the author
Cynthia Blumenthal is a regulatory engineer in California. She holds a master's degree in microbiology from San Francisco State University. Blumenthal is an ASQ member.