94
Engineering Systems Integration
structure on another object’s structure acts as a surrogate mechanism.
Therefore, the interface exposes a mechanism on the common boundary of
the two objects. That surrogate mechanism vanishes when the objects lose
their connection. Since mechanisms provide a means of exploiting the
transfer of EMMI between two objects, there is a potential advantage from
the perspective of another object that can in some way manipulate that
“exposed” mechanism. That advantage reveals itself an as additional capability not seen within the internal structure of an object. For example, a user
(object) may pick up a hammer (object). That the hammer rests on a workbench offers the user no advantage in driving a nail into a piece of wood.
The hammer is potentially available for use. That the user comes in contact
with the hammer (through the activity, “pick-up hammer”) takes advantage of the interface that joins the user’s hand and the hammer. The process
of the “pick-up hammer” is only achievable if the user’s hand (or logical
extensions by some other means) comes in contact with the hammer. The
capability that is not available to either of the two objects is enacted at the
moment of making a connection. It is the connectivity of two objects
through EMMI that results in a new capability. The capability exists
because of the interaction between the hammer and the user, while the
capability is said to be enabled by the act of connecting the hammer and
the user. That there is a connection reduces the degrees of freedom of both
objects. Reducing a degree of freedom is termed as a limitation, if the
reduction in the degrees of freedom is out of the control of the receiving
object. When an object is used (exchanging EMMI with another object),
both objects have a constraint imposed on them that was not operable (in
existence) before the interface was established. The limitations are different for each object. From the perspective of the send object, its internal
allocation of EMMI (e.g., output versus losses) is deemed a constraint. That
constraint results in output EMMI that is received by another object. The
receive object is limited by the input EMMI and in turn allocates the EMMI
according to its internal constraints. The primary difference between a
limitation and a constraint is the perspective from which the EMMI is
either input (limitation) or is allocated (constraint). The constraints are different for each object. When an object is constrained, a function results.
When there are multiple constraints, there are multiple functions.
From a functional perspective, a hammer and a piece of wood are dramatically similar. The difference between a solid metal hammer and a piece of
wood is related to the differences in the internal mechanism(s) of the two
objects. These differences result from their individual properties and traits.
For example, one object’s internal mechanism absorbs incident radiation
(EMMI) and converts it to heat, while another internal mechanism reradiates
that converted heat to beyond the physical boundary of that object. The other
object turns out to have very low thermal conductivity and reradiates very
little. Other differences in properties for the two objects, for example, are
the mechanisms of absorbing mechanical shock and the temperatures for
Engineering Systems Integration
structure on another object’s structure acts as a surrogate mechanism.
Therefore, the interface exposes a mechanism on the common boundary of
the two objects. That surrogate mechanism vanishes when the objects lose
their connection. Since mechanisms provide a means of exploiting the
transfer of EMMI between two objects, there is a potential advantage from
the perspective of another object that can in some way manipulate that
“exposed” mechanism. That advantage reveals itself an as additional capability not seen within the internal structure of an object. For example, a user
(object) may pick up a hammer (object). That the hammer rests on a workbench offers the user no advantage in driving a nail into a piece of wood.
The hammer is potentially available for use. That the user comes in contact
with the hammer (through the activity, “pick-up hammer”) takes advantage of the interface that joins the user’s hand and the hammer. The process
of the “pick-up hammer” is only achievable if the user’s hand (or logical
extensions by some other means) comes in contact with the hammer. The
capability that is not available to either of the two objects is enacted at the
moment of making a connection. It is the connectivity of two objects
through EMMI that results in a new capability. The capability exists
because of the interaction between the hammer and the user, while the
capability is said to be enabled by the act of connecting the hammer and
the user. That there is a connection reduces the degrees of freedom of both
objects. Reducing a degree of freedom is termed as a limitation, if the
reduction in the degrees of freedom is out of the control of the receiving
object. When an object is used (exchanging EMMI with another object),
both objects have a constraint imposed on them that was not operable (in
existence) before the interface was established. The limitations are different for each object. From the perspective of the send object, its internal
allocation of EMMI (e.g., output versus losses) is deemed a constraint. That
constraint results in output EMMI that is received by another object. The
receive object is limited by the input EMMI and in turn allocates the EMMI
according to its internal constraints. The primary difference between a
limitation and a constraint is the perspective from which the EMMI is
either input (limitation) or is allocated (constraint). The constraints are different for each object. When an object is constrained, a function results.
When there are multiple constraints, there are multiple functions.
From a functional perspective, a hammer and a piece of wood are dramatically similar. The difference between a solid metal hammer and a piece of
wood is related to the differences in the internal mechanism(s) of the two
objects. These differences result from their individual properties and traits.
For example, one object’s internal mechanism absorbs incident radiation
(EMMI) and converts it to heat, while another internal mechanism reradiates
that converted heat to beyond the physical boundary of that object. The other
object turns out to have very low thermal conductivity and reradiates very
little. Other differences in properties for the two objects, for example, are
the mechanisms of absorbing mechanical shock and the temperatures for