Concept map about how a thermostat works. Slightly adapted from http://cmap.ihmc.us/docs/linkingwords.html See how this changed after SD modelling at IM-736

Upgrade of Kermack–McKendrick Epidemic SIR Infectious Disease Model (circa 2015) - Metrics by Guy Lakeman

This is a simple SIR infectious diseases 3 stock model with Susceptibles, Infectives and Recovereds stocks. In the initial description the R signified Removed and could include Deaths, Recovered with immunity to infection (Resistant) or those who had fled the epidemic. Note the need to initiate the epidemic by adding a pulse of a single infected person at time 0.

Addition of a slider for susceptibles is equivalent to accumulated total cases

SARS, MERS AND COVID are similar virus types only differing in their sub genus

The COVID outbreak has reached 150,000 infected people

This simulation allows an attempt at predicting how long the virus will persist and its longevity dependence on its high speed massive infection numbers that have reached pandemic proportions

SARS reached 8,000 infected total and ran for 9 months before stopping

MERS 2012 is still killing 8 years later with patients dying even after using interferon to try and cure them

This is a stock flow map representation From Evans RG and Stoddardt GL  1990 paper Soc Sci Med 31(12)1347-63 , also published in a book by Evans, Barer and Marmor, Why are some people healthy and others not?: The determinants of population health See IM-425 for a simulation.

This is the Concept map at IM-735  modified to reflect the learning after system dynamics modeling at IM-393, 

Kidney replacement therapy dynamics: causal loop diagram of the kidney dialysis and transplant model extended to Chronic Kidney Disease from MOTOHASHI and NISHI Int. J. Epidemiology1991; 20: 1032-1036

Hannon and Ruth Modeling Dynamic Biological Systems p67

Addition of glucagon hormone action to control glucose homeostasis extended from IM-586

Hourly arrival pattern added to IM-663 A work in progress model for ED daily average flows based on reported statistics by triage category with all triage categories aggregated. Based on a hospital performance report from  http://www.bhi.nsw.gov.au/publications/hospital_quarterly_3 

See IM-8221 for Triage splits WIP

A work in progress model for ED daily average flows based on reported statistics by triage category with all triage categories aggregated. Based on a hospital performance report from  http://www.bhi.nsw.gov.au/publications/hospital_quarterly_3 

Go to Gene Bellinger's insight version with video link This common archetype of systems that include relapse or recidivism allows exploration of the unintended effects of increasing upstream capacity and swamping downstream capacity. The increase in the relapse rate eventually returns to swamp upstream capacity as well. A social welfare example, based on a TANF case study, from How Small System Dynamics Models Can Help the Policy Process. N. Ghaffarzadegan, J. Lyneis, GP Richardson. System Dynamics Review 27,1 (2011) 22-44 abstract Conference version here

Regulation of resource allocation to service in response to service quality. A non-price-mediated resource allocation system. From Sterman JD Business Dynamics p172 Fig 5-27

A general model of flows between hospital and the community with workshop elements. See also IM-3200 for focus on frequent presenters with mental health issues

A stock flow structure used to show the unit of analysis, scope of study and context of the ED Four hour rule project, cloned from im-399 monthly flows

Shows the causal loop diagram of the flow of organs from donors to recipients to explore places to improve the transplant rate

DIabetes incidence from population inflow, with undiagnosed and diagnosed stocks

Potential Diagnostic Error flows based on Schiff's Diagnostic Error Categories