The software versions you mentioned (5.1 and 4.40) likely refer to successive releases of WBS Schedule Pro or similar software, with each version offering improvements or new features over its predecessors.
For learning and implementing PERT and WBS effectively, you might also explore educational resources and training programs offered by project management institutions, such as the Project Management Institute (PMI) or Coursera, edX, and Udemy courses on project management. wbs schedule pro pert 51 crack and 440 better