The nature and effects of construction delays

A method for assessing delay claims, regularly used in the USA, is described, together with procedures which have been proposed for dealing with concurrent delays. These treatments are reviewed to identify their shortcomings which in some instances stem from a view of the nature of delays which is not consistent with the way in which delays actually occur. The various types of delay are examined to consider how these treatments might be amended to provide more realistic solutions. It is suggested that concurrent delays need only be separately considered when they affect a single activity, and the concept of parallel critical paths in an as-built network is thought to be invalid. The delays themselves are not always fixed in when they might have their effects and it is felt to be important that this be recognized. Finally a procedure is suggested to select days of exceptional adverse weather artificially, so that critical path method (CPM) analyses may be carried out.