The reason for litigation in probate administration is primarily due to one party (family member) NOT doing what they should, or obstructing things for various reasons.
There's an estate in Norfolk County, Norwood, MA where that is the exact problem. Proves again BE PREPARED. This man was influenced by his sister to draft documents making mother personal representative, when she had already indicated that she wasn't willing. May have to file a formal petition for probate, get citation and spend months resolving the issue of who will be representative of the estate. The wife is getting axed out by the sister, who's controlling the mother.
The sad reality is when dealing with someone's final affairs, you can't take for granted the fact that "it's family" or "they're nice people" or "they wouldn't do that" because, once there's money on the table, people react and things you never could have suspected, happen.