What support could an employer give to an employee who has been unsuccessful in an application for a promotion?

The employer should support an unsuccessful internal candidate to ensure that they remain motivated and develop so that they have a better chance of progressing in the future. The employer should give the employee feedback as soon as possible after the process so that the employee does not dwell on the failure. It should give the employee constructive criticism enabling the employee to take practical action to address their weaknesses. This should include an actionable development plan to address the areas that were identified as requiring improvement during the assessment process. Subject to the employee's approval, the employee's line manager could work with them to build the development plan, with support from HR. This could include ways of stretching the employee in their current role.