Is there inefficiency? Is there poor employee discipline? Is there ease of integration with other system you already have?

What type of business are you in? Will this technology help you or would something else serve you better? Who is going to measure your improvements.??

1. Ask for references, ideally in your industry, and call them.
2. Pay particular attention to how the vendor supports their product.
3. Stay away for newbie's. Longevity indicates the vendor is doing something right.

1. Get thorough demonstrations from all vendors
2. Consider how it fits or otherwise with existing reporting mechanisms/systems
3. Make sure costs and future development potential is understood

1 - low initial cost
2 - low ongoing cost per user
3 - preferably charged per transaction - so you can start slow and grow
QBIS does all 3

Review the size of the call centre you will be using the WFM tool for.
What benefits are you hoping to be able to give the business/workforce
Visit as many call centres as possible with possible WFM solutions