How to manage underperforming staff
Diagnosis first. Most attempts fail because the cause was assumed.
Most attempts to deal with an underperformer fail for one of two reasons. Either nobody ever defined what good looked like, or the manager diagnosed the wrong cause and treated it confidently.
You cannot identify underperformance without a baseline
Underperformance is a gap against a standard, which means the standard has to exist first. It needs to have been defined, agreed with the person and communicated to them, ideally at their last appraisal or during induction. Without that, any conversation about performance becomes a disagreement about expectations, and the manager loses it.
Evidence before conversation
Gather what actually shows the gap: samples of the work, previous appraisals, 360 degree feedback. The point is not to build a case against someone, it is to be able to describe the gap in terms they can examine rather than dispute. Once the gap is stated concretely, it becomes the thing you are both working on.
Diagnosis is where managers go wrong
A useful way to think about it is that performance is ability multiplied by motivation. Ability is aptitude plus whatever training and resources the organisation has provided. Motivation is desire combined with commitment. Because it is a product rather than a sum, either one at zero produces nothing, which is why the diagnosis matters so much.
The common and damaging error is treating a capability problem as a motivation problem. A manager concludes the person is not trying, applies pressure, and performance gets worse, because someone who lacks a skill does not acquire it under stress. The reverse error wastes training budget on someone who knows exactly how to do the job and has stopped caring why.
What to do
Act early, while the gap is still small and the conversation is still ordinary. Have the frank conversation rather than the comfortable one. Ask honestly what part of this is yours, because unclear objectives and absent feedback are management failures wearing an employee's name. Build a development plan together, with measures in it, and agree how and when you will both check progress. Document each step as you go.
What not to do
Do not let the follow up slide when something urgent lands, because an abandoned plan teaches the person that none of it was serious. Do not pour coaching into someone who denies there is a problem at all; that conversation has to be had first. Do not discuss an individual's performance with the rest of the team. And keep the respect and the confidentiality intact, because how this is handled is watched by everyone who is not in the room.
If ability is the cause
Whetten and Cameron's sequence is a practical order to work through. Resupply, meaning give them the resources the job actually needs. Retrain, where the skills have fallen behind the role. Refit, adjusting the job itself and reallocating tasks. Reassign to a role with different demands, which has to stay genuinely challenging rather than becoming a visible demotion. And release, where nothing available will close the gap.
If motivation is the cause
The same authors are brisker here: set clear performance goals, provide help and feedback against them, and if that has been done properly and nothing changes, part company. The honesty of that sequence matters, because motivation problems are the ones managers most often leave running for years.
How long should it take
It depends, and anyone who gives you a fixed number is guessing. The complexity of the job matters, as do your own procedures and any union agreements. So does the person's track record: someone who performed well for five years earns more patience than someone who never did. Organisational size and administrative capacity play a part. So do circumstances, because bereavement, depression and divorce all produce temporary underperformance that is not a performance problem at all.
Where this is taught
Managing underperformers is Module 7 of the Certificate in Performance Management, and development plans are Module 5. The course is about ten hours, online and self-paced, with an exam at a 70% pass mark, and it is USD 950 with a free trial module open first.