Cybernetics helps us understanding the nature of urban spaces with environmental and behavioural perception as the fundamental tools. Nowadays, unorganized encroachments of street vendors/ hawkers, slums etc. in urban areas are a growing problem in the developing countries of Global South, leading to conflicts and unplanned characteristics. This paper focuses on organizing the activities related to encroachments of street vendors/ hawkers occupying the sides of busy urban streets, by organizing the behaviour of the end users. An urban place can be analysed along with its users. Users behaviour during different activities gives different possibilities, proximal cues of an area, which can be formulated as self-sustaining and rotating 'System' and 'Sub-systems'. Street vending/ hawking on a busy urban street is related with many other sub-activities like buying of those goods and travelling simultaneously. These activities create a conflict and a situation of congestion and pandemonium. This paper will emphasise how environmental and behavioural perception can upgrade the 'System and Sub-systems' framed out of these hawking, buying and travelling activities, into an effective and flexible one with reduced nuisances by behavioural change. There is a question, "how people will react if their regular behaviour practice changes, will it be good to them or not?" Sometimes change in behaviour makes their activities easier, it is just the arrangement of what they want, what are the positive cues within their behaviour while doing the systematic activities or what they actually tend to.