Definition. Project Cost Management is a group of processes required to ensure the project is completed within the approved budget. Processes. There are following processes which are part of Project Cost Management. Resource Planning; Cost Estimating; Cost Budgeting; Cost Control
The definition of an arbiter is someone who is either qualified to judge or chosen to decide something. Jennifer Lopez is an example of an arbiter for the television show American Idol. 1  a person selected to judge a dispute; umpire; arbitrator.  a person fully authorized or qualified to judge or decide.
An arbitrator is a judge of the dispute and provides resolution measures which is binding on the parties. A mediator is more a facilitator who assists in developing options and achieving a mutually agreed resolution. He does not make a decision for the parties.