TMS (Transportation Management System) is a system that mirrors closely to transport operations in the physical world. This is also the reason why TMS is a really fun system to dabble with.

Visibility Management
A key physical part of TMS is the knowing where your orders are. In simple terms, TMS is a system that shows your order status and location. You can also find out when your order is expected to depart and arrive.
Networked Data
TMS helps to integrate various transport related information into a single platform. Instead of calling many parties for these information, TMS can pull the information into a single data repository. Thus, you will only need to focus on managing exception scenario like road flooding.
Freight Audit
Like the physical world, the ability to playback the transportation for audit purpose is essential. Transport orders or signing of delivery are some of physical activities that are digitised in TMS for compliance.
In a nutshell, you can think of TMS as the digital transformation of your transportation business. The advantages outweighs the cons as you can now view your physical world virtually in TMS.