WPS is enforced through a single mechanical check. The Salary Information File you submit to your bank gets matched against the contracted wages registered with the Ministry of Labor. A field in the wrong position, an identifier that doesn't match, a rounding error in the trailer total — any one of these rejects the file. When the file is rejected, your salaries don't leave the bank, and your business is hours away from a labor ministry warning.
Most payroll software bought into Qatar wasn't built for this. It was built for the US, the UK, or India, with WPS added later as a configurable export. The difference between "configurable WPS" and built-in WPS is the difference between a payroll cycle that works and one that breaks every other month.