Network Diagram as the Best and the Most Suitable Project Schedule - Assignment Example

? Project Management France Vacances Task Gantt chart Gantt chart is the pictorial view of all the activities written on y-axis and its timeline on x-axis. The timeline is shown in days and the duration of each activity is hilited in the form of a bar. All activities are arranged in sequence on the basis of its priorities determined by the predecessors given for each activity. The flow of activities is shown with a pointed arrow. Microsoft Project is used to make the Gantt chart. Task 2: Network Diagrams Network Diagram is the graphical view of all the activities designed in Microsoft Visio. Each activity is represented in the form of a box having seven cells. Three cells on top, a full width cell in the middle showing Activity name and three cells on bottom. Each of these cells represents important information about the activity as shown below in the picture:- Calculation of Early Start and Early Finish time: Early start time in the first activity is set to 1 whereas duration is given in the requirements. Early finish time is calculated by adding duration in early start time. Early start time of the next sequential activity is set to the previous activity’s early finish time. Adding duration, Early Finish time is found. All activities are traversed in the forward direction and their early start, duration and early finish time is found in this way and written in their respective cells. Early start time of activity that is approached by two or more activities is set to the highest time. For example Activity 14 is approached by Activity 8 which has early finish time as 76 and Activity 12 which has early finish time as 39. The highest early finish time is 76 so early start time of Activity 14 is set to 76. Calculation of Late Start and Late Finish time: Reaching to the end of the activity or finish traversing is restarted in the backward direction. The last activity’s early finish time is set to its late finish time. Deducting duration, late start time is set. Traversing backward previous activity’s late finish time is set to the late start time of the current activity. Then deducting duration, late start time of previous activity is found. All activities are traversed in the backward direction and their late finish, float/slack and late start time is found in this way and written in their respective cells until the start is reached. Late finish time of activity that is approached by two or more activities is set to the lowest time. For example Activity 5 is approached in backward direction by Activity 6 which has late start time as 22 and Activity 7 which has late start time as 65. The lowest early finish time is 22 so late finish time of Activity 5 is set to 22. Calculation of Float or Slack time: The Float or Slack time is the difference between late finish and early finish time. It is same as the difference between early start and late start time. All the activities that have float/slack as zero is critical activity and must be part of the Critical Path. Start and Finish Activity box: Each diagram begins with the start box having values of zero for early start, duration, early finish, late start, float and late finish. Each diagram ends with the finish box having values of maximum days needed to complete for the project. It is set in all the cells of early start, duration, early finish, late start, float late finish. Directional Arrow: Each activity is linked with a directional arrow to show the sequential flow of the activities. The arrow can be in the forward direction to show the progress of work flow or up and down direction to show the parallel works. No backward direction is allowed in the network diagram because the time once passed never returns. Task 3: Constraints of Days and Amount Applying constraint of completing project within 70 days has forced to break up two of the activities. Activity 6 of 15 days which has been now changed to Activity 6(a) and Activity 6(b) each of 10 days duration calculated by 2/3*15 formula given in constraints. Similarly Activity 8 of 39 days is now changed to Activity 8(a) and Activity 8(b) each of 26 days duration. The revised network diagram is shown in Task 4 which has a critical path of 67 days only. The total cost of the project to be completed now in 67 days is ?14,400 which is well within the budget of ?14,400. The activity wise cost calculated in excel is produced in Task 5 Task 4: Revised Network Diagram with Critical Path and completion time as 67 days Task 5: Project cost calculated for each activity Activity Duration days Cost ?80 per day Activity 1 001 ?80 Activity 2 002 ?160 Activity 3 000 ?0 Activity 4 006 ?480 Activity 5 010 ?800 Activity 6(a) 010 ?800 Activity 6(b) 010 ?800 Activity 7 005 ?400 Activity 8(a) 026 ?2,080 Activity 8(b) 026 ?2,080 Activity 9 010 ?800 Activity 10 010 ?800 Activity 11 024 ?1,920 Activity 12 012 ?960 Activity 13 006 ?480 Activity 14 006 ?480 Activity 15 004 ?320 Activity 16 003 ?240 Activity 17 002 ?160 Activity 18 000 ?0 Activity 19 000 ?0 Activity 20 004 ?320 Activity 21 003 ?240 Total work days 180 ?14,400 Task 6: Report on Activity Break-ups The first phase of developing the network diagram as shown in Task 2 draws the Critical Path in which project completion time is found as 85 days. There are two constraints in this project. The first constraint requires that the project is completed within 70 days. The second constraint requires that the total cost of the project is below ?14,600 The first constraint is about finishing the project within 70 days. To apply this constraint, the break up of any activity that is found suitable is allowed into two sub activities. However duration of each of the sub-activity is restricted to two-third of the whole activity. The process used to select the activities for break-up begins with the study of the available path for completing the project and its float. The study shows following available paths for completion of the project:- No. Path of activities in sequence 1. Activity 1 1d, Activity 2 2d, Activity 17 2d, Activity 4 6d, Activity 5 10d, Activity 6 15d, Activity 8 39d, Activity 14 6d and Activity 16 3d 2. Activity 1 1d, Activity 2 2d, Activity 17 2d, Activity 4 6d, Activity 5 10d, Activity 7 5d, Activity 12 12d, Activity 14 6d and Activity 16 3d 3. Activity 1 1d, Activity 2 2d, Activity 17 2d, Activity 4 6d, Activity 5 10d, Activity 6 15d, Activity 9 10d, Activity 13 6d, Activity 15 4d and Activity 21 3d 4. Activity 1 1d, Activity 2 2d, Activity 17 2d, Activity 4 6d, Activity 5 10d, Activity 6 15d, Activity 10 10d, Activity 14 6d and Activity 16 3d 5. Activity 1 1d, Activity 2 2d, Activity 17 2d, Activity 4 6d, Activity 5 10d, Activity 6 15d, Activity 11 24d, Activity 14 6d and Activity 16 3d 6. Activity 1 1d, Activity 2 2d, Activity 17 2d, Activity 4 6d, Activity 5 10d, Activity 6 15d, Activity 20 4d and Activity 21 3d It is observed in the first network diagram that the only path in which all the activities have float as zero is at no. 1 and it is the Critical Path of the project. All other paths are therefore eliminated for shortening of the completion of the activity list to be selected for breaking up into two sub-activities. The activities that are left for breaking up into two sub-activities are Activity 1 having duration of 1 day, Activity 2 having duration of 2 days, Activity 17 having duration of 2 days, Activity 4 having duration of 6 days, Activity 5 having duration of 10 days, Activity 6 having duration of 15 days, Activity 8 having duration of 39 days, Activity 14 having duration of 6 days and Activity 16 having duration of 3 days. The restriction of two-third duration for sub-activity and doubling of its cost implies that all those activities that have duration upto six days are not feasible for selection. This eliminates activities 1, 2, 17, 4, 14 and 16. The activities that are left for selection are No. 5 of 10 days duration, No. 6 of 15 days duration and No. 8 of 39 days duration. Activity 8 is selected in the next phase as it has highest duration. Breaking this activity into two sub-activities (a) and (b) into two-third days gives duration of 26 days for each of the two sub-activities. This saves 13 days calculated by deducting duration of sub-activity of 26 days from the original activity of 39 days. This also reduces the total project completion time by 13 days bringing it down to 72 days. (85 days – 13 days) In order to reduce completion time by further 2 days, the next available activity No. 6 is selected which has duration of 15 days. Breaking this activity into two sub-activities (a) and (b) into two-third days gives duration of 10 days for each of two sub-activities. This saves 5 days calculated by deducting duration of sub-activity of 10 days from the original activity of 15 days. This also reduces the total project completion time by 5 days bringing it down to 67 days. (72 days – 5 days) The total project completion time of 67 days in the Critical path satisfies our first constraint of completing project within 70 days. The revised network diagram reconstructed by showing early start and end time, late start and late finish time and float for each of the activities after adding sub-activities for Activity 8 and Activity 6 as Activity 8(a) and Activity 8(b) and Activity 6(a) and 6(b) is given in Task 4. The second constraint is about total cost of project. In the first phase of calculation the total number of days of the project was calculated as under:- Activity Duration days Cost ?80 per day Activity 1 001 ?80 Activity 2 002 ?160 Activity 3 000 ?0 Activity 4 006 ?480 Activity 5 010 ?800 Activity 6 015 ?1,200 Activity 7 005 ?400 Activity 8 039 ?3,120 Activity 9 010 ?800 Activity 10 010 ?800 Activity 11 024 ?1,920 Activity 12 012 ?960 Activity 13 006 ?480 Activity 14 006 ?480 Activity 15 004 ?320 Activity 16 003 ?240 Activity 17 002 ?160 Activity 18 000 ?0 Activity 19 000 ?0 Activity 20 004 ?320 Activity 21 003 ?240 Total work days 162 ?12,960 Breaking Activity 8 into two sub-activities each of 26 days increases cost of activity from 39 days to 52 days. The cost of 39 days comes to ?3,120 where as cost of 52 days of two sub-activities comes to ?4,160 increasing the total cost of the project by ?1,040. This makes the total cost of the project to ?14,000 (?12,960 + ?1,040) which is below the given constraint of ?14,600 Breaking Activity 6 into two sub-activities each of 10 days increases cost of activity from 15 days to 20 days. The cost of 15 days comes to ?1,200 where as cost of 20 days of two sub-activities comes to ?1,600 increasing the total cost of the project by ? 400. This makes the total cost of the project to ?14,400 (?14,000 + ?400) which is below the given constraint of ?14,600 Both the constraints of completion time and project cost are now achieved into the revised network diagram and therefore it is the best and the most suitable project schedule. Read More