Abstract: A master project file and one or more sub-project files are merged to form a merged master project file while avoiding date shifting, pointers to external files, accommodating equally named resources and calendars and accommodating split tasks which may otherwise be caused by differing settings or defaults for files created or modified on different processors or other incompatibility between the master project file and sub-project files by copying data reconstructed from the original settings, defaults and the like of the original sub-project file to descriptive fields in the merged master project file to resolve settings which must match between the master project file and the sub-project file while altering names of tasks or files as necessary and validating merged task data against the copied data.