However, should you be called upon to justify a formalized approach, you can point to the following list of 15 problems that are likely to occur without it. The project is loosely organized, individual task frames are vague. Deadlines are set by external forces. Scheduling is based on task duration, not actual effort. Tasks are fitted between chosen milestones and within available timeframes.
Resources are unknowingly over-allocated.
No formal method for estimating is used. There's no standard or schedule for status reporting. Frequent slippage is experienced on projects. Difficulties are encountered in adjusting schedules. There's informal coordination of resources, at best.