Objective should be strategic; benefits need to be in dollars
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perhaps include examples to illustrate
For example, your objective can be:
Become the market leader from the current second place
Become the lowest cost producer in your market segment from the current mid-level
Improve customer satisfaction ranking to the second ...
Benefits can also be objective and measurable, ie, SMART.
I look at the difference between the two from a business case perspective is that the objective is your independent variable and benefit is the dependent variable. You perform the work to achieve the objectives and then those objectives will influence achieving the benefits at some time in the future.