There are a lot of different reasons why people purchase workflow systems. Generally they break down into a few major categories: To reduce costs, to provide better service to their customers, or regulatory requirements.
To Reduce Costs:
When you automate a process or maximize the use of resources you start to save money, and that is generally where most of the savings can occur. However often money is saved because workflow systems can be easier to understand then traditional systems and less training and knowledge is required. This helps you save money because if you have high staff turn over you are saving on training costs. Costs can also be saved by centralizing information into one place with one common data access paradigm so that users always know the right place to look for something, thus saving further time. Mobility can also save you money if you have a web based workflow system.
To provide better customer service:
With a web based workflow system you can offer your clients better real-time reporting on various things like: How their orders are progressing or how much they have spent with you this quarter. As such they will also spend less time calling you time find out how things are going and this can save you many man hours.
Some people want a new toy. OK this may be the worst reason to purchase workflow software but that is not to say it doesn't happen.
Some people just want a tool to model their processes so they can see what is going.
Some people buy because their competitors have bought something. Again maybe not the best reason.
Reporting on workflow throughput can give management better information and guide them towards better decisions.
Can allow for greater collaboration especially if it is web based.