How important is Employee Performance Management for an organization to succeed?

human capital is the life blood of any organisation and directing them towards the company's objectives is not just a top priority of the organisation but an essential functions of management . here employee performance management doesn't not exactly mean increasing the amount of paper work for the manager .It should be a more habitual work of the supervisor or immediate manager to keep a check on his subordinates and their ideas for the organisations success 

Employee Performance is intrinsically tied to Organizational Performance whereby individual contributions lead to group results! If performance is not managed at the individual level, then group targets wouldn't be achieved ultimately impacting organizational performance. A simple example is that of a Salesman. When he achieves a high Sales Revenue, automatically the Organizational Performance goes up and vice versa! 

Hi, Performance evaluation is to identify and address differences in human resources so management can benefit the human resource in achieving organizational goals

Well,

it is a top priority. Without a "perfect" management is like having a body wothout  a brain.

I think it is very important