I always take a realistic viewpoint on this question because there are many factors that go into the perk chart when we make a detailed schedule. Some of the issues that affect the delivery can totally be out of the control of the machine builder or the buyer of the equipment.
For example, the most common delays I see are either getting the proper permits or securing the electric service by the time the equipment arrives. The first installation I ever did we had all the equipment installed and ready for test operation but we had no three phase power. It took an additional four weeks waiting time for the regional electrical service company to install the three-phase power into the building. The main 3 phase power was on the electric pole only 150 Ft. (46 m) from the building! The buyer of the equipment planned two months earlier for the electric service installation and was told by the electric utility company installation time should be done in one week. Scheduling utility companies to do work for industrial installation moves of electrical 3 phase power lines is not like calling your local electrician. Generally, you have no control over the big utility companies, they tell you when they will come.
Other real life situations that occur are new building construction delays by contractors due to weathers or conditions.
For overseas shipments, I have seen cargo containers delayed by weather or by customs holding the goods at their port for up to six weeks in one case.
Typically, from the time you order the equipment to the time the machinery is actually making products I recommend you plan three months. The big concrete batching plants take up to five to eight months to be up and operating from placement of order. This naturally depends on the size and what level of facility you are installing. I have seen the plants shipped, installed and making products much faster but I believe you should be realistic in your goals.
Remember there is a difference between getting the machinery installed and operating and then getting your people trained in making good quality products everyday learning the business of operating and maintaining machinery.