Sistem Dinamis Pertemuan 8
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Transcript Sistem Dinamis Pertemuan 8
Roesfiansjah Rasjidin
Program Studi Teknik Industri
FT - UEU
Pendahuluan
Feedback merupakan konsep inti dari
system dynamics.
Causal loop diagrams merupakan suatu tool
penting untuk merepresentasikan struktur
umpan-balik sistem
Manfaat Causal Loop Diagram
Menangkap dengan cepat hipotesis-hipotesis
penyebab dinamika
Mendapatkan atau menangkap model-model mental
dari individu atau tim
Mengkomunikasikan umpan-balik penting yang
diyakini berperan atau bertanggunjawab terhadap
suatu masalah
Notasi Causal Loop Diagram
Birth Rate
+
+
+
Population
R
B
Fractional Birth
Rate
Death Rate
+
-
Average
Lifetime
R
Clockwise, positive or
reinforcing loop
B
Counter-clockwise, negative or
balancing loop
Link Polarity
Symbol
+
X
Y
X
Y
Interpretation
All else equal, if X increases (decreases),
the Y increases (decreases) above (below)
what it would have been. In the case of
accumulations, X adds to Y.
All else equal, if X increases (decreases),
then Y decreases (increases) below (above)
what it would have been. In the case of
accumulations, X subtracts from Y.
Mathematics
Examples
+
∂Y/∂X > 0
Births
Population
∂Y/∂X < 0
Deaths
Population
Guidelines for CLD
Causation versus Correlation
Include causal relationships between the
variables; do not include correlations between
variables
Labeling link polarity
Determining loop polarity
Name your loops
Indicate important delays in causal links
Guidelines for CLD
Variable names
Should be nouns or noun phrases
Must have a clear sense of direction
Choose variables whose normal sense of direction
is positive
Guidelines for CLD
Maximize the clarity and impact of CLD by using a
good layout (graphic design)
Choose the right level of aggregation
Don’t put all the loops into one large diagram
Make the goals of negative loops explicit
Distinguish between actual and perceived conditions
DISKUSI DAN TANYA JAWAB