NA 78 has been revisedfrom 2023-02-27
Abstract NA 78 ‘DCS update, upgrade and migration from the user perspective’
Control system suppliers regularly introduce new control system product lines or system versions to the market. New control systems are not always fully compatible with existing systems, so that there may be a substantial need to replace components.
Users of control systems are faced with the question of how to protect investments that have been made. Installed systems should, on the one hand, continue in operation and be expandable, but users also wish to share in the technical options new systems offer.
Control system suppliers speak of migration where a move from one system to another occurs, or in the case of a change of a system component. They provide so-called migration strategies in such cases. The user must then examine whether the migration strategy meets his needs. The following recommendations are intended to provide users with support during this consideration.
The problem of a product change in the case of control systems is intensified by the by the current use commercially-available IT products. The rapid pace of development of these devices (processors, operating systems, networks, graphic software) has an enormous effect on the control system product spectrum. Service life cycles of control system components are shortened as a result. This tendency becomes particularly clear in the area of monitoring and operating components, where products with different hardware and software platforms can even be on offer within a control system range over a time period of a few years.
Several system changes should therefore be expected during the service life of a chemical plant. This means that the migration strategy of control system suppliers should be evaluated during the initial system selection phase.