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FIGURE 12.14
Process Model
The relationship data input
between data data output
and control DFDs
models
[HAT87]

PSPECs
process
activators

data
Control Model
conditions
CFDs

CSPECs
control output
control input

Data flow diagram Control flow diagram

Absolute tank Converted Check &
pressure pressure convert Above
pressure pressure
Check &
convert
pressure
Max
pressure

PSPEC
If absolute tank pressure > max pressure
then
set above pressure to “true”;
else
set above pressure to “false”;
begin conversion algorithm x-01a;
compute converted pressure;
end
FIGURE 12.15
endif
Data conditions
316