Without trying particularly hard, you can probably think of multiple occasions where you did something you didn't want to do or didn't agree with, just because your boss told you to. So why won't your employees just suck it up and do what you're asking (telling?) them to do without all this resistance and complaining? Well, first off, they probably already are doing things just because you told them to - you just don't know about it. And secondly, there is a reason you can so easily remember those times when you had to toe the party line: it's not pleasant to feel like you have to check your brain at the door. It's true that you have formal authority at your disposal to force people to do things, but that will mostly get you the minimum. If you want to get your employees' best work, you'll need their buy-in and trust. This will also be important when you have to ask them to do something unpleasant or illogical, so that they'll be willing to pitch in for you.
Any time your team is dealing with a project or decision that will significantly impact them, you will need to get commitment and buy-in from the whole team on what is to be done, even those not directly affected. (Those are probably the employees who will be asked to pick up any slack that the affected employees can't handle, so they will be affected eventually.) The most effective way to get commitment is by building consensus. Wait! Don't roll your eyes or check out yet. Consensus doesn't mean everyone loves the idea or that the team is having a group hug. Consensus merely means that everyone has had an opportunity to provide input and is clear about why the outcome is what it is. They may still disagree with the decision, but they have agreed to support it (or at least not undermine it).
The following tips can help you get buy-in from your employees, even if it's an unpopular decision.
Set aside time to have a discussion.
Yes, you're busy and the team is already swamped, but you will lose so much time and productivity due to resistance and offline discussions that you will be better off surfacing things now when you can address them publicly. Take an hour now to save yourself a lot of hours and quality issues later.
Clearly convey to employees what the purpose of the discussion is.
Is it to determine what the decision will be, or to discuss as a team how to effectively handle and mitigate the consequences of a decision already made? Being clear about what is and isn't on the table will help focus their energies and reinforce your credibility. Approach the discussion with an open mind. Your employees are smart people, and they may have important points to make. Treat them like the adults they are, and they may surprise you with their ability to adapt to challenging circumstances.
Provide information about the context.
It's easy to forget that your employees have a different vantage point than you (and each other) and sometimes don't know the larger context of their work. They may also not be aware of business constraints that your upper management might be dealing with, since they are hopefully sheltered somewhat from those issues. Help them to see the bigger picture, and it will not only help in gaining their commitment but will also make them better employees because they'll be able to provide better ideas and suggestions.
Ask each person to share what they see as the positives and negatives of the proposed action or decision.
This could be rewards and risks, pros and cons, advantages and disadvantages, etc. The key is that each person needs to weigh in on both the positives and the negatives, so that you're surfacing their underlying concerns and getting them to think beyond their pet issues as well. Even if they agree with what others have said, get them to state specifically what they agree with and why they agree. Manage the discussion so that each person has about the same amount of time to speak, and cut people off if needed. "I can tell you have a lot of thoughts on this issue, Tom, and I do want to hear them. I need to hear from each of the other members of the team, too, so please jot down some of your additional thoughts while they're fresh, and we'll come back to you after the others have spoken if they haven't mentioned everything on your list." It might be a good idea to start with people who are in the middle as far as talkativeness - don't put the introverts on the spot right away, but don't let the extreme extroverts be the first to speak, either.
Express empathy with their frustrations but try to keep them focused on what they have control over.
Try to balance letting them vent with more constructively focusing on action. It's also important not to undermine your reporting chain, even if you disagree with what they're doing. "Yes, I know it seems illogical to pull resources from our product line to devote to product B, but I'm sure Charlie has good reasons for making that decision. As a senior VP, he has access to a lot more information than we do at this level. It's going to be challenging for us to deal with the reduced budget, but let's see if we can come up with some creative ways to cut corners and still meet our targets. What are your ideas?"
Conclude the discussion with a concrete, clear decision or next action.
Everyone should leave the meeting knowing exactly what came out of the discussion, and why the final result is what it is. "Thanks for the concerns you guys have raised about the potential risks to our deadline for Project X. Since we are not able to change the resources available to us, I will propose to Charlie that we will need to either change the deadline or take Project W off our plates for now. If he says no to both items, we will need to expand on some of the ideas you have brought up for where we can cut corners. Until I get that decision, we will need to continue on our current path as best we can. Is everyone clear about what they are expected to do next?"
If not everyone got a chance to speak and the discussion had to be ended abruptly, then convey when it will be continued. "We didn't get a chance to hear from Bianca or Trey, so let's reconvene for half an hour at 11 tomorrow to continue this discussion. I know nobody wants another meeting, but it's really important that we think this through thoroughly so that we can be prepared." (Having to do this once or twice will help motivate you to cut off the employees who dominate the discussion next time.)
There will be times where you can't have a discussion, namely when the action has to happen within a matter of hours. (Being busy isn't a reason to not have the discussion.) In those cases, you'll need to be honest with your team and acknowledge that you know you're asking them to do something that might not be the best course of action but you need them to do it anyway. A boss of mine who did this very effectively would use the phrase "check the box," as in "Yeah, I know it doesn't make sense, but this is one of those times where we just need to check the box and get it done." What was helpful about that is it acknowledged the situation and gave me permission to not invest a lot of energy and time. I may not have done the minimum, but I certainly didn't do the maximum in these situations. Your employees will appreciate your candor, and if you've shown that you care about their input in other situations, they'll trust that you really can't discuss this particular situation with them.
Consensus and innovation
Building consensus isn't just about being nice or diplomatic. It's a method for more effective decision-making and making the most of the resources on your team. If done well, it results in higher morale and greater innovation, which will help you and everyone on the team to be more successful, not matter what ridiculous decisions might be made by the folks above you.