Where multiple connected systems form a one big more complex system that has all its parts affecting each other, while designing we need to take into consideration that we should not design a solution to a problem in isolation of its affection on other system’s subsystems.
Opened systems: less sustainable, that is when a system uses outside item and generate waste without a feedback in lifecycle loop.
However, two opened systems can be part of overall sustainable system if the output of one system is an input of another opened system, however, if at one point the project team mistakenly considered the output as a waste then the entire system is no longer sustainable.
Closed systems: the most sustainable with closed loop, generating no waste.
Affecting how systems work:
Leverage Point where small or inexpensive action done leads to higher impact to the whole system.
Positive and negative feedback loops: the system output can normally either stop the system or trigger it to work once again that is either positive or negative.