There really is no set process or timeline for the disciplinary process and many thing can impact how long it takes and what needs to take place. In addition to the attitude and actions of the member who is undergoing the process, there are other things that play a role. Each individual Bishop impacts the process. The culture of a ward, the stake and the area also impact the process. What may be completed in 5 months in a BYU ward may take a year in a family ward in California.
Remember also that inspiration comes from many places. A bishops own experiences, education, knowledge and wisdom, in addition to what he hears and sees around him is where he will draw judgement in addition to the inspiration of the holy spirit.
Also, when a member is disfellowshipped or excommunicated there are actually two process at work that, while intertwined, are really independent of one another. The first is the repentance process. This process is taking place between the person and their Heavenly Father, with the help of our savior and the spirit. A bishop, stake president or the prophet himself can not set a timeline on this or tell you whether your repentance is complete. This process could be over in weeks or months or in the case of Paul, just a couple days.
The second part is the disciplin or punishment part which can and will take longer. While the Lord promissss us that when we repent fully that HE remembers no more, man isn't quick to forget or forgive so the disciplinary process will likely go on for a longer period of time, even once the person has fully repented.
A couple of the comments above are a bit short sighted and even possibly reference a catch 22 type of mentality where they suggest that if a person is anxious or inquiring as to when the process will be over then they aren't ready. It is my observation that too many disciplinary process linger on longer than they should and the lack of structure an communication on the part of priesthood leadership help cause this. I have heard leaders use terms like "you're so close" or "you're almost there" like repentance is a destination instead of a process we all must undergo.