 The basic principles of ISO 14001 are based on the well-known Plan-Do-Check-Act (PDCA) cycle.Prior to implementing ISO 14001, an initial review or gap analysis of the organization's processes and products is recommended, to assist in identifying all elements of the current operation, and if possible, future operations, that may interact with the environment, termed "environmental aspects".Environmental aspects can include both direct, such as those used during manufacturing, and indirect, such as raw materials.