How can HR and business-unit leaders strike the right balance between data analysis and authentic knowledge of employees in order to build a strong workforce?

People Analytics has become a hot topic recently. Companies such as Google have made great strides in the use of data to guide their hiring and promotion decisions.
How does your organization integrate “hard” and “soft” metrics when assessing performance and placement/promotion opportunities?
How can HR and business-unit leaders strike the right balance between data analysis and authentic knowledge of employees in order to build a strong workforce?
Include examples from the course materials as well as your own experience to support your position.