In this article I will discuss a simple COVID-19 outbreak control system.
This control system involves a cycle that must be run through continuously: As quickly and as often as possible, so to speak.
The operating system is shown schematically in below figure.
At national level, a government takes decisions on measures to be taken, based on scientific advice and political considerations (1).
The main approach is laid down in a strategy (2).
Trade-offs underlie political considerations (3). The longer this process is stretched out over time, the higher the cost to the economy; that is one of the tradeoffs, a government must make. On the longer term social stability can become an issue.
In the Netherlands, the choice is made to ensure that everyone at all costs receives adequate medical care to minimize the number of fatalities. That is a strategic choice.
In practice, this means that the intensive care (IC-) capacity may not be exceeded; that is the critical capacity in the process, which the Dutch government tries to manage (4). If the use of this capacity is exceeded, sufficient care cannot be provided.
To avoid overloading of the IC-capacity, the contamination-rate (5) must be managed and for that reason, the outbreak must be delayed.
It is now fairly well-known what percentage of the number of infected people, need intensive care (capacity). A certain critical value of contamination must not be exceeded (6), so as not to exceed the available IC-capacity.
A number of control measures is available to governments and societies to regulate the infection rate (7). Ranging from lockdowns, closure of restaurants, prohibition of large gatherings to social distancing, etc.
It is problematic that often it is not (yet) known what the effectiveness of these measures is, that their effect has often been delayed, and that the controllability (8) of the system (society) has limitations due to all kinds of (sometimes unknown) effects that occur (for example because of nonlinear responses, or because measures are not implemented due to a lack of cooperation or discipline).
Not only are sufficiently effective steering and control measures required (requisite variety), the availability of control information is also crucial.
Without accurate and timely information (9) of the current state of affairs, and of the effect of control measures, it is not possible to manage effectively and efficiently, and achieve the desired results.
On the basis of this information, the strategy and the effectiveness of the measures can be evaluated; models can be improved. This evaluation can also lead to adjustments to the strategy or rescheduling.
The availability of information is a problem in the Netherlands: the need for testing is ignored. This lack of information detracts from the effectiveness of controlling the outbreak.
Organization and coordination between governments (national, provincial, municipal, etc.), ministries, government services, and also suppliers of critical items (for example fans, face-masks) are also important.
The effectiveness of the organization must also be periodically evaluated to increase the effectiveness and efficiency of the approach.
The situation evolves continuously.