When a couple decides to separate, or if they have been separated for awhile, the child custody arrangement has a note of finality to it. However, if you and your child's parent are sure that you'd prefer to raise your child from separate households, it's good to make the arrangement official. Without an official child custody arrangement in place, there is nothing holding either parent to their obligations. This can quickly cause strife and unnecessary stress.
A child custody arrangement in official standing can put to rest some of the issues many parents may argue or have uncertainty about. Child support, child custody (both physical and legal), schedules and other things can be pre-determined in hopes of creating the best solution for the child. Other people involved will be considered, but if their wishes do not meet the criteria for best interests of the child, it will likely be nixed.
An official child custody arrangement can hold a parent accountable. If it's reported that a parent isn't upholding their side of the arrangement, it can result in consequences. Holding a parent accountable is sometimes part of the process for a child's parent. While it may not be enjoyable, it could be in the best interests of the child.
The hope is that a child custody arrangement goes smoothly and leads to a happy, healthy outcome for everyone involved. However, as many families know, it's not always that simple. Hopefully instances of disagreements or failure to meet expectations will be few and far between. If the need arises, that's what the child custody order is for, to outline obligations and responsibilities in addition to rights of both parents and child.