Abstract: Object-oriented approaches to programming have their own scope of applicability. For a number of tasks, preference is traditionally given to classical methods of structured programming. These preferences are not uncommon in a deterministic world and in machine-representation-oriented systems. Historically, classical methods developed from von Neumann's architecture of machine representation.
While solving the problems of deterministic world the advantage of approaches, opposite to OOP is shown. For example, the Oberon modular language and system in classic distribution demonstrate minimalistic way of reliability, which differs from vast majority of program systems maximizing amount of features supported. Data-oriented programming technology also steps aside traditional object-oriented paradigm because data from code separation is needed. The instrumental approach proposed by author is linking Oberon technologies with data-oriented programming, keeping interface interaction mechanisms from OOP. The instrument with no data, but associated with data is introduced instead of an object. MultiOberon restrictive semantics makes an opportunity to turn off OOP restriction and switch on instruments usage. Instrument is instantiated automatically on program module loading. Instrument is queried either by its type or by the type of record associated. All the functionality is implemented in MultiOberon compiler. Instrumental approach was used for SCADA-platform software development, which targets complex automation and diagnostics. It is used in dynamically loaded plugins for data types matched shared memory data types.
The instrumental approach offers a different branch of development from OOP for the classic Oberon programming language and the classical approach