Use a base for random numbers to set an initial point for Minitab's random number generator. A base is useful when you want to select the same random sample to evaluate, or generate the same set of random data more than one time. For example, you and a colleague want to generate the same random sample to evaluate.
Minitab has a long string of random numbers available. If Minitab always started at the same point, you would always get the same data. To avoid this, Minitab uses the time of day (in seconds or fractions of a second) to choose a random starting point in the string.
If you use the same base with different releases of Minitab, you may not get the same random number sequence.