Regardless of the nature of the statistical and methodological underpinnings of the value-added modelling, the impact upon policies, practices and outcomes can be negligible or even negative if an effective implementation is not undertaken. This belief was evident in a number of countries involved in the development of this project and led to more detailed analysis of the methods for implementing a system of value-added modelling. Part III of this report builds on the discussion presented in Part I and Part II to provide a guide for the implementation of a system of value-added modelling in education systems. Such a guide is not a definitive list, nor will each aspect be applicable to all education systems. Rather, it builds on the knowledge gained both in various education systems and from the expert group who have experience in implementing systems of value-added modelling in various education systems.