When making your schedule for piling operations, always keep in mind that the pile rig is a heavy and large equiupment therefore it will probably need special permits for transportation. This means additional approval time for a permit, additional cost and also just a specific window (usually night time of a certain day) that the pile rig can be transported. Also you need to make sure that all the piling operations are properly finished because once the rig is gone, it is very hard to get it back for the reasons explained above. You also need to make sure there is enough accessable area on your site for the pile rig. This not only included the area that the pile will be driven but around it too. The ground condition is also another important factor. This is a very heavy equipment so if there had been rain for instance, the ground can be soft and therefore you need to make sure that the soil that the pile rig will stand on can carry the weight of the pile rig. usually for clay type soils a rainy period man mean a lot of delay plus some remediation of the soil at least for the first top few feet in order to carry the weight of the pile rig. Another important factor to remember i sthat you should arrange the pile driving operations so that the pile rig will not travel over the driven piles. Although I have seen pile subs saying that they did it a million times and nothing will happen, still, if you ask to a structural engineer, he would say no.