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Essences of Interaction
The term “function” includes what something is used for (i.e., user intent),
what it could be used for (i.e., design intent), in addition to what it was accidentally used for (Ariew 2002) (i.e., opportunistic intent). Function can be
understood as belonging to one or more of these categories. Function is
defined relative to a particular stakeholder’s perspective. For example,
from the point of view of a developer, the function of a subsystem A might
be the interface between two subsystems B and C. But from the point of
view of a user who wants to encourage the adoption of a new interface
protocol, subsystem A may be their only means to guarantee payment of
license fees for use of their protocol. Both functions (interfacing subsystems
B and C and enforcing payment for using protocol) are ascribed to the same
set of objects and are adequately defined, although they may differ in performance and quality based on the stakeholder’s perspective. The set of objects
for one function should be considered from the various stakeholder perspectives and represented as dependent representations of overlapping functions
mapped to the same set of objects.
A system function may have any number of performance parameters and
likewise several quality requirements associated with each performance.
Functions can be added, deleted, or changed. The output EMMI from a single object that interacts with a second object to produce another output, the
totality of outputs is called performance. Specifically, this performance is the
performance of the function. As a means of accountability, performance
measures aid in understanding how well functions achieve their goals.
Performance measures allow for comparative ratings from which to determine similarities between functions.
A function occurs because of the interaction between two objects, commensurably at the physical interface between two objects. The interaction of EMMI
between two objects enables an output (performance) that is dependent on the
mechanisms of two objects acting across their common interface. If provision
is made (designed and architected into the product or service) then a user may
access that interface and be enabled to “use” the function, but not the interface.
It is important to realize that while being respectful to the prevalent emphasis
on interface specifications, the key issues for integration reside with the enactment of functions (their connectivity, coupling, and cohesion) and not solely
with the transfer of data between objects. Functions can be compared by their
combined performances of the two objects. For example, two cars racing on a
dirt tract have various measures one of which is determinable by the winner
of the race, that one crosses the finish line before the other (assuming both cars
started at just after the signal to begin the race). The race event involves two
cars, each performing their individual functions of ‘to race.’ The objects of the
two cars and the starting line from the start of the race; and the function of ‘to
race’ for each car is formed by a car’s interaction with the dirt tract. The performance of that interaction helps determine the change in speed of each car.
The performance of the process of racing is comparable to other processes. The performance of the process of one car racing is to either win or
Essences of Interaction
The term “function” includes what something is used for (i.e., user intent),
what it could be used for (i.e., design intent), in addition to what it was accidentally used for (Ariew 2002) (i.e., opportunistic intent). Function can be
understood as belonging to one or more of these categories. Function is
defined relative to a particular stakeholder’s perspective. For example,
from the point of view of a developer, the function of a subsystem A might
be the interface between two subsystems B and C. But from the point of
view of a user who wants to encourage the adoption of a new interface
protocol, subsystem A may be their only means to guarantee payment of
license fees for use of their protocol. Both functions (interfacing subsystems
B and C and enforcing payment for using protocol) are ascribed to the same
set of objects and are adequately defined, although they may differ in performance and quality based on the stakeholder’s perspective. The set of objects
for one function should be considered from the various stakeholder perspectives and represented as dependent representations of overlapping functions
mapped to the same set of objects.
A system function may have any number of performance parameters and
likewise several quality requirements associated with each performance.
Functions can be added, deleted, or changed. The output EMMI from a single object that interacts with a second object to produce another output, the
totality of outputs is called performance. Specifically, this performance is the
performance of the function. As a means of accountability, performance
measures aid in understanding how well functions achieve their goals.
Performance measures allow for comparative ratings from which to determine similarities between functions.
A function occurs because of the interaction between two objects, commensurably at the physical interface between two objects. The interaction of EMMI
between two objects enables an output (performance) that is dependent on the
mechanisms of two objects acting across their common interface. If provision
is made (designed and architected into the product or service) then a user may
access that interface and be enabled to “use” the function, but not the interface.
It is important to realize that while being respectful to the prevalent emphasis
on interface specifications, the key issues for integration reside with the enactment of functions (their connectivity, coupling, and cohesion) and not solely
with the transfer of data between objects. Functions can be compared by their
combined performances of the two objects. For example, two cars racing on a
dirt tract have various measures one of which is determinable by the winner
of the race, that one crosses the finish line before the other (assuming both cars
started at just after the signal to begin the race). The race event involves two
cars, each performing their individual functions of ‘to race.’ The objects of the
two cars and the starting line from the start of the race; and the function of ‘to
race’ for each car is formed by a car’s interaction with the dirt tract. The performance of that interaction helps determine the change in speed of each car.
The performance of the process of racing is comparable to other processes. The performance of the process of one car racing is to either win or