NEMA in section 2(4)(b) requires that environmental management must be integrated, acknowledging that all elements of the environment are linked and inter-related and it must take into account the effect of decisions on all aspects of the environment and all people in the environment by pursuing the selection of the best practicable environmental option. This in effect requires a holistic evaluation of any project.

Holistic evaluation does not mean that a project must be looked at as a whole. It rather means that it must be accepted that there is a whole into which a project introduced. Thus a catchment may be the whole while the factory positioned on the banks of the river in the catchment is the factor introduced into the whole. The introduction of such a factor invariable causes a ripple effect. It changes the interaction between the other component parts of the whole and this causes a change in the thrust of the development of the whole.

Holistic evaluation requires that the probable thrust caused in the development of the whole by the introduction of the new project should be identified and defined. If this new thrust in development is beneficial, the development is acceptable. If the indications are that the thrust could have major adverse effects, the project must be reconsidered and where appropriate replanned or relocated to avoid an adverse impact or to ensure a beneficial impact.