For the expansion of the network with the addition of more activities, the range-names do not have to be redefined because they are initially set up to accommodate a network of 200 activities. The maximum number of activities in a project network that can be solved in a spreadsheet using this approach and the layout presented in this paper is the maximum number of columns possible in the predecessor matrix. Since the predecessor matrix can start only at column I, (The previous columns are needed for other information on the input data) the upper limit on the number of activities possible in modern spreadsheets is 248 (column IV – column I).