I personally pay a petsitter 25 bucks a day to come once a day and count heads, fill feeders, and check waters. I also give any eggs collected to her as a bonus.
If I am gone only a couple days (3 or less) I know the water will be fine since it a constant flow waterer, but I will add 1 extra feeder, fill up all feeders to the tip top, and also add a flock block in the run.
I also add a few squash to the run, those sometimes take more than a day to get eaten. My flock also has free access to free range areas, so they will never really run totally out of all available food.
I would have to say, if your gone a full week, you might want to consider having someone come over and care for them. Leave a very detailed list of feed- how much, what kind, how often, and how many birds you have, and what time they need to be in at night. Always let a caregiver know if you may have ANY predator problems, just in case, it may help them to know what to look out for, as well as keep them on their toes when it comes to caring for your flock.
I hope this helped!