This paper has demonstrated that the suggested coordination methods can be used for distributed on-line optimising control within a real time environment. Problems relating to system transient and local decision unit asychronisation, and their effects on system stability and convergence, have been investigated and methods for dealing with these problems are suggested. The convergency, accuracy and robustness properties of each coordination method have been discussed. Engineering judgement is needed to choose a particular coordination method with feedback to best suit the class of problem concerned. Further research should look into other coordination methods with feedback and to develop stablising control techniques for the decision units under asynchronous operation, so as to reduce the waiting time in the infimal level and the information exchange between the two levels.