This is definitely a post of me venting and thinking out loud. There are some things that really need to get done around the office and as a part of the infrastructure of the church I work at. And for these things to happen there is a reliance on volunteers. We have a great group of people at the church I work at that give tons of their resources to out community. But at the end of the day, they are volunteers. They are busy with familiy, careers and life in general. But for the sfuff to get done that needs to get done. We need those volunteers. They will need to be pushed beyond what they are currently doing. This is tough. I never know what is too much pushing or what is not enough. I just know that I am going to have start to push on some things.
A Pastor's Thoughts 
Yikes! You really sound frustrated. I think the question is this: Is your frustration valid (are some people dropping the ball) or is it the result of your expectations on how and when other people choose to or can get the things done that need to get done?
If they’re dropping the ball, then something’s gotta change. Renegotiate the deliverables or the timeline. Add a co-chair or support system. Reprioritize. Shift the paradigm. Chunk the tasks into smaller, more manageable bites. Delegate some of the tasks to others. Give a specific to-do list vs. a vague assignment since many people are far more tactical than visionary. Admit that sometimes the right person is in the wrong role. And don’t forget to pray that God would rise up leaders, change hearts, create urgency and use ordinary, fallible to do extraordinary kingdom work.
Also, it helps to realize that on the one hand, leadership of any kind can sometimes feel like babysitting. On the other hand, leadership requires holding people accountable. I think balancing those two things in grace and truth is a real challenge and, at least in the business world, it’s what separates “boss” from “leader.”
One other thought … just like successful and effective delegation is a learned skill for the leader, so, too is problem-solving, critical-thinking and embracing responsibility for the volunteer or the person serving.
My advice? Be patient with those who take a little longer to learn, train and equip those who need more of it, make the assignment fit the skill set, and continually praise the small successes. All of that goes a long way toward edification of both individuals and the body of Christ.