An airborne warning and control system is being built as part of a large defence project. The project comprises two main sub-systems (a) detection sub-system and (b) guidance subsystem. In implementing the project, the following precedence relationships must be adhered to: 1. Calibration of machines precedes production, independently for each sub-system i.e., (a) Calibration of machine 1 must be done prior to production of detection sub-system. (b) Calibration of machine 2 must be done prior to production of guidance sub-system. 2. Testing of detection sub-system can only be done after production of detection subsystem and testing of electronic controls. 3. Testing of guidance sub-system can only be done after production of guidance subsystem and testing of electronics controls. 4. Projectile testing can be started immediately after calibration of machine 2 is completed. 5. Assembly of detection and guidance sub-systems as well as ground control co-ordination can be started only after the testing of both sub-systems has been completed. 6. Preparation of final test gear involves several complex assemblies and can be initiated at the beginning of the project. However it must be completed before final testing can start. 7. Final testing requires the completion of assembly of detection and guidance subsystems, ground control co-ordination, and projectile testing. The time required to complete the various tasks of the project are given in the table below: TABLE 1: Tasks and Activity Times (a) Identify the immediate predecessor activities for each task in Table 1 and develop a project network. (b) Determine the earliest and latest start and finish times for each activity. Identify the critical activities which if delayed will delay the overall completion time of the project. (c) Which activities should definitely be completed by week 15 if the project is not to be delayed? An airborne warning and control system is being built as part of a large defence project. The project comprises two main sub-systems (a) detection sub-system and (b) guidance subsystem. In implementing the project, the following precedence relationships must be adhered to: 1. Calibration of machines precedes production, independently for each sub-system i.e., (a) Calibration of machine 1 must be done prior to production of detection sub-system. (b) Calibration of machine 2 must be done prior to production of guidance sub-system. 2. Testing of detection sub-system can only be done after production of detection subsystem and testing of electronic controls. 3. Testing of guidance sub-system can only be done after production of guidance subsystem and testing of electronics controls. 4. Projectile testing can be started immediately after calibration of machine 2 is completed. 5. Assembly of detection and guidance sub-systems as well as ground control co-ordination can be started only after the testing of both sub-systems has been completed. 6. Preparation of final test gear involves several complex assemblies and can be initiated at the beginning of the project. However it must be completed before final testing can start. 7. Final testing requires the completion of assembly of detection and guidance subsystems, ground control co-ordination, and projectile testing. The time required to complete the various tasks of the project are given in the table below: TABLE 1: Tasks and Activity Times (a) Identify the immediate predecessor activities for each task in Table 1 and develop a project network. (b) Determine the earliest and latest start and finish times for each activity. Identify the critical activities which if delayed will delay the overall completion time of the project. (c) Which activities should definitely be completed by week 15 if the project is not to be delayed
