First, let's clarify something important: past experience does not predict future performance. In fact, according to a large study analyzing 81 recruitment cases, the correlation between past experience and future performance is very low - just 0.06.* Despite this, many still view prior experience as one of the most important prerequisites for a job.
If you want to keep that kind of requirement, it’s important to be more specific about the exact experience you’re looking for. Simply writing "five years of experience" isn’t effective because it doesn’t convey what that experience should entail. You might be asking for five years in a similar role, but you need to be more concrete. Which experiences from a similar position are essential for you and your organization?
The second reason not to include "five years of experience" is that years do not necessarily reflect skill level. Many people have had experiences where they learned more in three months than they did over an entire year. If you ask for five years of experience, it could be five years where the candidate hasn’t actually learned much. Conversely, you might find candidates with just one year of experience who have gained a lot in a short time because they were deeply involved in the relevant tasks that you also have on your desk for the candidate.
Thirdly, no two jobs are the same. Even if a candidate has experience in a similar role, all the contextual factors surrounding the job will differ. Anyone who has changed jobs knows that the processes around tasks can vary. Maybe the clients are a bit different, or perhaps there are different IT systems in place. There are so many variables that even if the job looks similar, everything surrounding the job will be different, so it doesn’t make sense to simply require "five years of experience in a similar position."
If you choose to hold on to specific experience as a predictor of future job performance, you need to be clearer about which experiences you’re seeking.
If both you and the candidate know exactly what needs to be accomplished – instead of just having "five years of experience in a similar role" – your chances of an efficient and successful recruitment process increase significant.
*Van Iddekinge, C., Arnold, J., Frieder, R., & Roth, P. (2019): “A meta-analysis of criterion-related validity of prehire work experiences” Personnel Psychology, 72, 571-598. https://onlinelibrary.wiley.com/doi/abs/10.1111/peps.12335