CEO, Corp Dev, CFO, HR
Bring in key people together such as HR, CFO, CEO, Corp Dev, or even Board Members.
There are times when a non-core business is a part of the long-term strategy of the organization. Your goal is to identify the non-core business which is not aligned with the long-term vision of the company.
This is where your CFO comes in. After identifying the non-core business units, assess their profitability. Is the business underperforming compared to its potential? You can compare the actual performance to the market opportunity. This is how you will be able to determine if your business is running optimally.
Lastly, and probably most importantly, you need to determine if the business unit is severable. Is it possible for this business unit to stand alone on its own, or is it too reliant on your core business?