### 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
R
Clockwise, positive or
reinforcing loop
B
Counter-clockwise, negative or
balancing loop
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
Determining loop polarity
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
```