Job descriptions are a common and accepted tool for finding the right person to fill a vacant position. Talk to any business owner and they'll most likely tell you the biggest challenge they face is keeping a qualified staff in place to properly run their business. Job descriptions may or may not be the best way to do that.
Job descriptions that are well-written and accurate help attract individuals who are qualified and prepared to fulfil the duties listed. Sometimes it even helps prepare the individual for the interview questions or the general structure of the interview process. A good job description makes the interview process faster and easier with a better group of qualified candidates.
Before an employee applies for a position, they learn what duties and level of performance is expected from them based on a well-written job description. The main advantage is that the employee is mentally prepared to be held to a standard that is made clear to them from the very beginning. This allows them to be productive in the eyes of their supervisor, and it gives the supervisor a way to measure their progress.
Because job descriptions have a list of specific duties and expectations for performance, the employee is naturally discouraged from deviating from it. The job description subjects the employee to procedures, rules and required methods. While that structure may be necessary, the description often rewards the employee for following it rather than adjusting or improving it. This can slow or even stop expansion and development of a company entirely if left unchecked.
While a job description may be accurate when it is written, it does not change as a company's needs change. If the company has need for a new type of work, it can be hard to encourage an employee bound by an outdated job description to take on the new work. Updating job descriptions can be time-consuming since they need to be updated every time a change is made. This is particularly a problem in fast-paced industries that deal with volatile markets or technology.