You have a problem that project management software can't solve. Replanning is not planning, it is scrambling.
You need to find out why the shop misses every deadline. Some possibilities include:
1.The deadline was established with out talking to the shop and was an unrealistic expectation.
2. The shop was never told of the deadline or the importance of the deadline.
3. The shop knew of the deadline, thought it was attainble, but due to unforseen circumstances couldn't meet it.
4. The shop knew of the deadline, knew it was important, knew it was acheivable, but didn't make it any way.
Somebody needs to get involved with the shop. Go to the shop See how it works . Have someone explain the process. Explain about the delays. Ask for their input. Next project be sure to do the following:
1. Explain the project, not just the tool& die portion. Explain the overall schedule. Get their input on durations and dates for the schedule. Don't schedule their work with out talking to them.
2.Once the schedule is done talk to them about it.Find out how much lead time they need to start. If the shop is told to start2 1/2 weeks before their 2 week project is due, and it takes 6 weeks to get materials, that might be part of the problem.
3. Establish dates for the shop for various points in the work. Talk to the shop in advance of these dates so if their are delays you can be proactive to avoid them. Go to the shop at least three times during the process to inspect the work. If it is not important to you, it won't be important to them.
4. Document everything. If they are suceesful, go to the shop and thank them. If they are not dicuss it with the shop, then with your supervisor.
This sounds like there may be serious management issues here. However, it sounds like an oppertunity for the guy who fixes the problem. Just remember this is management problem, not a software issue.
Good Luck!