so there are some other answers here that deal with, you know, your actual question. I'm more interested in the whole "not sending the employee on the trip" aspect. Just go to the end if you want my answer to your actual question though.
Penalising an employee out of the blue is a terrible management decision.
From what i'm reading here, everything about this is a terrible decision.
Now, I don't know much about this business trip you're talking about, but you write
problem is, they have been led to believe they would be going on an important business trip in the following month. I don't think this would be beneficial for them - and I suspect they think it's more of a holiday than a professional opportunity
It's that last bit - the bit about holiday vs professional opportunity - that makes it sound like this business trip is more a perk than some sort of mission-critical thing. Which means that you're now withholding a perk to penalise an unaware employee.
You also write
When the team was setup, they were promised certain benefits such as cash bonuses and visiting industry conferences.
Which, look, it makes it sound like this was a decision that
- you weren't part of
- is a senior management decision that represents part of overall compensation
which implies to me that it's really not your place to be withholding the benefit either. After all, you don't just get to "not pay" an employee for a week's work if it wasn't great work, do you?
So from this, I've gathered (perhaps erroneously):
- You are penalising an employee instead of talking to them as some sort of way to "crack the whip"
- The employee has been authoritatively told that there would be a business trip, and that it is effectively part of their overall compensation
- You are now publicly withholding promised compensation as a way of "cracking the whip", and also publicly rewarding someone else with said reward.
Overall, I think this is a bad strategy.
You're sending a signal that there should be infighting and ego pieces instead of collaborative work done to "get the goodies" - the best get rewards, the worst get nothing. You're also showing that management has taken a stance that past promises should not be viewed as set in stone.
If any employee (the bad employee, the good employee, any employee) was unsure about the company, this is going to be a warning klaxon. Management "just deciding" to change their mind, without rhyme or reason, is always a bad sign. Pitting employees against each other is often a bad sign (depending on industry, i mean. Sales would be an industry where this is expected. IT or PR? not so much).
I wouldn't be overall worried about the employee's relationship with other people in this team, I'd be worried about the overall message you're sending out, and the effect it will have on employee trust of management.
If this employee is terrible, just fire them. Or take steps to improve them (and honour the promised trips). But don't keep them on and then deny them their promised compensation, because that makes management look bad to everybody.
To answer your question, give the employee a bunch of easy targets to hit (but at a level that is higher than they are at now), with the promise that if they hit them they'll make the next trip. That gives them something easy to hit, improves their confidence and shows you're focussed on helping them. It will also help you keep your eye on the employee. The whole 'denying this trip" is still a bad idea, I think, but this just makes a slightly positive spin on things.
Finally, if you're offshore from them, do you know why the employee is performing poorly? Is he/she being bullied or misrepresented?