Decision rule

If Cash Return on capital   > cost of capital →Accept the project and

If Cash Return on capital < cost of capital ->Reject the project

This can be generalized to look at the return to equity investments. Adding depreciation & other non-cash charges to net income, you can derive the cash equity income. Therefore,

Cash Equity Income = Net Income + Depreciation & other non-cash charges

Cash Return on Equity =   Cash Equity Income /Average Book value of total investment in project

Decision rule :

If Cash Return on Equity > cost of Equity ->Accept the project and

If Cash Return on Equity < cost of Equity ->Reject the project