Paul Solomon's Performance Based Earned Value has a co-author- Ralph Young. His book is The Requirements Engineering Handbook . This book is a guide to the development of requirements. Requirements elicitation is critical to any project be it agile or not. Pp. 154-155 discuss a bit about agile requirements and presents some Home Grounds for both the agile and disciplined approaches to requirements.
The comparison terms of agile and disciplined are probably not the best, since agile processes require discipline - possible more discipline - Table 7.7 on p. 155 does provide a nice side by side comparison. Especially in the enterprise and ERP domain "managing" requirements - whether they are emerging or not - is a critical success factor. While there are many good reasons for this, one of the most important ones is the connect any and all changes to requirements to the business case and back to the Earned Value (BCWP) components of the business case.
By making the connection between business value derived from the capabilities of the deployed system, to the costs of developing that system, to the Earned Value of the components produced from the investment of that cost - the project managers are able to make informed decisions about trade offs in the presence of emerging or changing requirements. This is the basis of any Systems Engineering trade studies approach. An approach not yet common in the IT and software development business, but at the heart of aerospace and defense systems.
It answers the question
What is the value of a decision in the presence of risk, cost, benefit, requirements compliance and opportunity?
If the project team is responding to emerging requirements, or reacting to customer requirements changes without the ability to do the trades then they are simply following the will of the customer - and possibly blindly following the will of the customer, because the customer may be just as uninformed about the trade space as the development team. As well this is the basis of Real Options in the context of Project Portfolio Management.