Level 5, the enterprise level, is where centralized IT systems and functions exist. Enterprise resource management, business-to-business, and business-to-customer services typically reside at this level. Often, the external partner or guest access systems exist here, although it is not uncommon to find them at lower levels (for example, level 3) of the framework to gain flexibility that may be difficult to achieve at the enterprise level. However, this approach may lead to significant security risks if not implemented correctly.
The ICS must communicate with the enterprise applications in order to exchange manufacturing and resource data. Direct access to the ICS is typically not required. One exception to this would ...
