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Importance of Integration
by its nature these early first-look integrations are designed to be an iterative means of filling in until the test-ready object can be made available.
Ad hoc scheduling reduces the orderliness of integration to a somewhat
chaotic clustering of objects that seem ready but lack their reciprocal objects
from which to build functions. There are two strategies from which to proceed.
First, the objects that seem ready for integration may be shelved until their
counterpart objects also seem to be ready to be integrated, at which time the
two objects may begin the integration process. Alternatively, an emulator
may be constructed that presumes to match the as-yet-completed object and
integration may proceed with the seemingly finished object with that of the
simulator. When the as-yet-completed object seems ready, the two objects
can be integrated together or, should there be other circumstances that prohibit that type of integration, the second object can also be integrated to a
like-kind emulator. The procedures of using emulators to perform integration is time-consuming, problematic, and never quite the same as integrating the intended objects. The most significant difference between an
emulator and the “real” object is noticed in the performance of the emulator.
Typically, the performance of an emulator is significantly slower than the
“real” object. For example, during the development of a new microprocessor
chip, emulators are used by software developers to test their code before the
microprocessor chips have been returned from the foundry, packaged, and
tested.
Principle 7: The Principle of Loss
When two objects are integrated, both objects give up some measure of autonomous
behavior.
For every action there is a loss (the law of action*). That loss is quantifiable
as EMMI. When two objects interact, there is a loss. When two objects are
integrated, energy is expended (there is a loss). When EMMI is transferred
from one object to another across an interface, EMMI is expended. Interaction
is different from integration and integration is different from interaction.
There must be interaction to accomplish integration; however, an interaction
does not portend the integration of two objects. In either case, EMMI is
expended. Interaction and integration are covered in more detail in Chapter 2.
Whether integration for a system or integration for a system of systems,
there are fundamental questions regarding the losses incurred to sustain
operations of the system. An analysis of losses is a means of discussing what
it takes at the system level to operate. What is the amount of EMMI expended
to achieve various levels of performance?
Further, there are fundamental losses that arise in a system of systems
integration that are not apparent in integrating a system. In a system of systems, integration is different than that of a system. Integrating a system into
* This could be considered Newton’s fourth law of motion.