Software Engineering

10.2.6 
Control structures
Control structures provide the means for guiding execution flow to perform a data 
processing task accounting for the conditional treatment of data processing inter-
mediate results. From the operational model perspective, control structures repre-
sent business rules or operational procedures that determine how a process should 
be executed. Within the functional architecture, control structures represent the 
decision or computational logic that determines how the data processing execution 
should proceed. The general control structures are as follows:
●
 
Branch—
a path of execution involving a sequence of data processing tasks or 
functions.
●
 
Concurrency—
enables multiple threads of behavior or branches to be initiated 
and executed in parallel.
●
 
Selection—
enables one thread of behavior to be initiated based on some condi-
tional argument.
●
 
Iteration—
enables a thread of behavior to be repeated one or more times.
●
 
Trigger—
activates an action, process, or series of events.
These control structures have comparable constructs implemented by most com-
puter languages. However, for the purposes of establishing the functional architec-
ture, it is not desirable to adhere to the implementation-specific control constructs. 
A concurrency is analogous to task synchronization in the Ada and C
++
 programming 
languages. A selection represents an 
If
 (
If…Goto
, 
If … Then, If … Then … Else
) 
or 
Case
 statements in most programming languages. Iteration represents a loop 
mechanism similar to 
For … Next, Do While, Do Until
, or 
ForEach
 (collection 
control loop) in most programming languages.