3. In the “EST-EFT” sheet, row 9” the current last row with an activity in it, is copied to row 10 and then column J, the current last column with activity F, is copied to column H. The order of copying is important to avoid circular reference. Since the activity names in this sheet are connected to the activity names on the input sheet (The formula in cell A4 of this sheet is “Inputs ! A3” which is copied down the rows for the other activities and the formula for cell E 2 is “Inputs!2” which refers to the activity names at the top of the predecessor matrix, in the “Inputs” sheet. It is then copied across the other columns), no other editing is necessary. The resulting “EST – EFT” sheet with the updated EST-EFT pairs for all the activities is shown in Figure A4.