(4) Critical Path Method Project Tool (4) Critical Path Method Prof. Dr. Christian Bleis 1 Interaktionskompetenz

Finding the critical path from project start to project end CPM – goals Main goals Finding the critical path from project start to project end Economically feasible cut this path How do I want to fulfill the Project goal?? Prof. Dr. Christian Bleis 2 Interaktionskompetenz

Process-Arrow Network Arrows = tasks, operations, process CPM – design Process-Arrow Network Arrows = tasks, operations, process Knot = event, milestone, stage Starting stage End stage Task Duration of the task How do I want to fulfill the Project goal?? Prof. Dr. Christian Bleis 3 Interaktionskompetenz

CPM-Example (forward + backward calculation) (3) Calculate material costs 1 3 3 3 4 10 11 (7) Determine cost of sale (1) Order supplies 5 3 (4) Delivery (time) of the materials Start 5 7 16 16 5 (6) Calculate personnel costs Goal (2) Set up the work plan (8) Work execute 6 5 2 (5) Instruct co-workers 4 Duration of the task 5 6 4 10 10 Earliest date on which the Process can be completed Latest date on which the Process can be completed Prof. Dr. Christian Bleis 4 Interaktionskompetenz

5 (6) Steps to create a CPM-Diagram CPM planning involves the following steps: Specify the individual activities. Determine the sequence of those activities. Draw a network diagram. Estimate the completion time for each activity. Identify the critical path (longest path through the network) Update the CPM diagram as the project progresses. Prof. Dr. Christian Bleis 5 Interaktionskompetenz

Step 5: Identify the Critical Path (a) 5 (6) Steps to create a CPM-Diagram Step 5: Identify the Critical Path (a) The critical path is the longest-duration path through the network. The significance of the critical path is that the activities that lie on it cannot be delayed without delaying the project. Because of its impact on the entire project, critical path analysis is an important aspect of project planning. …  Prof. Dr. Christian Bleis 6 Interaktionskompetenz

Step 5: Identify the Critical Path (b) 5 (6) Steps to create a CPM-Diagram Step 5: Identify the Critical Path (b) The critical path can be identified by determining the following four parameters for each activity: EST earliest start time: the earliest time at which the activity can start given that its precedent activities must be completed first. EFT earliest finish time, equal to the earliest start time for the activity plus the time required to complete the activity. LFT latest finish time: the latest time at which the activity can be completed without delaying the project. LST latest start time, equal to the latest finish time minus the time required to complete the activity. …  Prof. Dr. Christian Bleis 7 Interaktionskompetenz

Step 5: Identify the Critical Path (c) 5 (6) Steps to create a CPM-Diagram Step 5: Identify the Critical Path (c) The slack time for an activity is the time between its earliest and latest start time, or between its earliest and latest finish time. Slack is the amount of time that an activity can be delayed past its earliest start or earliest finish without delaying the project. The critical path is the path through the project network in which none of the activities have slack, that is, the path for which ES=LS and EF=LF for all activities in the path. A delay in the critical path delays the project. Similarly, to accelerate the project it is necessary to reduce the total time required for the activities in the critical path. Prof. Dr. Christian Bleis 8 Interaktionskompetenz

Step 6: Update CPM-Diagram 5 (6) Steps to create a CPM-Diagram Step 6: Update CPM-Diagram As the project progresses, the actual task completion times will be known and the network diagram can be updated to include this information. A new critical path may emerge, and structural changes may be made in the network if project requirements change. Prof. Dr. Christian Bleis 9 Interaktionskompetenz

Example Task (No. 1) Critical Path Method Interaktionskompetenz Prof. Dr. Christian Bleis 10 Interaktionskompetenz

CPM-Example 1. Complete the foreward Calculation of the following CPM Diagram (3) Calculate material costs 1 3 . . 3 .. .. (7) Determine cost of sale (1) Order supplies 5 5 5 (4) Delivery (time) of the materials Start 5 .. .. . . 8 (6) Calculate personnel costs Goal (2) Set up the work plan (8) Work execute 3 4 2 (5) Instruct co-workers 4 Duration of the task . . 4 .. .. Earliest date on which the Process can be completed Latest date on which the Process can be completed Prof. Dr. Christian Bleis 11 Interaktionskompetenz

CPM-Example 2. Complete the backward Calculation of the following CPM Diagram (3) Calculate material costs 1 3 5 . 3 12 .. (7) Determine cost of sale (1) Order supplies 5 5 5 (4) Delivery (time) of the materials Start 5 17 .. . 8 (6) Calculate personnel costs Goal (2) Set up the work plan (8) Work execute 3 4 2 (5) Instruct co-workers 4 Duration of the task 4 . 4 10 .. Earliest date on which the Process can be completed Prof. Dr. Christian Bleis 12 Interaktionskompetenz

CPM-Example 3. Mark the Critical Path 5 9 3 12 12 5 5 5 17 17 8 (3) Calculate material costs 1 3 5 9 3 12 12 (7) Determine cost of sale (1) Order supplies 5 5 5 (4) Delivery (time) of the materials Start 5 17 17 8 (6) Calculate personnel costs Goal (2) Set up the work plan (8) Work execute 3 4 2 (5) Instruct co-workers 4 Duration of the task 4 4 4 10 14 Latest date on which the Process can be completed Prof. Dr. Christian Bleis 13 Interaktionskompetenz

CPM-Example (forward + backward calculation) (3) Calculate material costs 1 3 5 9 3 12 12 (7) Determine cost of sale (1) Order supplies 5 5 5 (4) Delivery (time) of the materials Start 5 17 17 8 (6) Calculate personnel costs Goal (2) Set up the work plan (8) Work execute 3 4 2 (5) Instruct co-workers 4 Duration of the task 4 4 4 10 14 Earliest date on which the Process can be completed Latest date on which the Process can be completed Prof. Dr. Christian Bleis 14 Interaktionskompetenz

Example Task (No. 2) Critical Path Method Complete the foreward Calculation of the following CPM Diagram Prof. Dr. Christian Bleis 15 Interaktionskompetenz

CPM-Example 1. Complete the foreward Calculation of the following CPM Diagram (Jenny, Abb. 4.05, S.341) Prof. Dr. Christian Bleis 16 Interaktionskompetenz

CPM-Example 2. Good, now complete the backward-Calculation of the CPM Diagram Errechnen der Zeitwerte und Bestimmung des kritischen Weges: Zeitwert der Vorwärtsrechnung: Beginn bei 0 dann: addieren der Zeiteinheiten nach der logischen Reihenfolge und Eintrag in das linke untere Feld des Ereigniskreises Bedeutung: Bestimmung der frühesten Ereigniszeitpunkte (Jenny, Abb. 4.05, S.341) Prof. Dr. Christian Bleis 17 Interaktionskompetenz

CPM-Example 3. Mark the Critical Path (Jenny, Abb. 4.05, S.341) Zeitwerte der Rückwärtsrechnung erhält man nach Abschluss der Vorwärtsrechnung. Anhand des kumulierten Ergebnisses wird der Netzplan rückwärtsgerechnet. Zeitwert der Rückwärtsrechnung: vom Endereignis und dessen Zeitwert aus der Vorwärtsrechnung ausgehend Bestimmung der spätesten Ereigniszeitpunkte durch Subtraktion der Zeitwerte Eintrag in den rechten unteren Teil des Ereignisknotens (Jenny, Abb. 4.05, S.341) Prof. Dr. Christian Bleis 18 Interaktionskompetenz

CPM-Example 3. Mark the Critical Path (Jenny, Abb. 4.05, S.341) (Jenny, Abb. 4.05, S.341) Prof. Dr. Christian Bleis 19 Interaktionskompetenz

Benefits + Limitations of CPM Prof. Dr. Christian Bleis 20 Interaktionskompetenz

CPM provides the following benefits : Benefits of CPM CPM provides the following benefits : Provides a graphical view of the project. Predicts the time required to complete the project. Shows which activities are critical to maintaining the schedule and which are not. Prof. Dr. Christian Bleis Interaktionskompetenz

Limitations of CPM CPM was developed for complex but fairly routine projects with minimal uncertainty in the project completion times. For less routine projects there is more uncertainty in the completion times, and this uncertainty limits the usefulness of the deterministic CPM model. Prof. Dr. Christian Bleis Interaktionskompetenz

Are there other ways to visualize network planning? Prof. Dr. Christian Bleis 23 Interaktionskompetenz

Starting with the CPM-Example (3) Calculate material costs 1 3 3 3 4 10 11 (7) Determine cost of sale (1) Order supplies 5 3 (4) Delivery (time) of the materials Start 5 7 16 16 5 (6) Calculate personnel costs Goal (2) Set up the work plan (8) Work execute 6 5 2 (5) Instruct co-workers 4 Duration of the task 5 6 4 10 10 Earliest date on which the Process can be completed Latest date on which the Process can be completed Prof. Dr. Christian Bleis 24 Interaktionskompetenz

Inventor: Morgan R. Walker and James E. Kelley (1957) PERT – goals and design Main goals Monitoring of processes by checking the times of milestones Stage-Knot-Network Arrow = duration Knot = event, result, milestone, stage Stage duration Inventor: Morgan R. Walker and James E. Kelley (1957) Question to be answered: What do I want to achieve during the Project? Prof. Dr. Christian Bleis 25 Interaktionskompetenz

personnel costs calculated PERT (with the same example) 1 3 1 Material- und personnel costs calculated Material ordered 4 3 3 10 11 3 5 1 7 5 Project start Project goal 16 16 2 4 6 5 Material delivered and workforce instructed Work plan set up 4 5 6 10 10 Prof. Dr. Christian Bleis 26 Interaktionskompetenz

Inventor: Morgan R. Walker and James E. Kelley (1957) MPM– goals and design Main goals Visualizing of complex processes with high interdependencies Task-Knot-Network Arrow = correlation (and/or duration) Knot = tasks Tasks.-No. Task Earliest finishing time Earliest starting Time EST duration EFT Inventor: Morgan R. Walker and James E. Kelley (1957) LST LFT Latest starting Time Latest starting Time Prof. Dr. Christian Bleis 27 Interaktionskompetenz

Metra-Potential-Method (MPM) (3) Calculate material costs 3 4 7 6 10 (7) (1) Calculate costs of sale Order Material 10 5 15 3 3 (4) 11 16 3 Supply time of the material (0) 3 1 7 10 3 10 Projectstart Project goal (6) 16 16 Calculating of personnel costs (2) 5 5 10 (8) Do the job Set up work plan 6 11 10 6 16 5 5 10 16 1 6 (5) Instruct work force 5 4 9 6 10 Prof. Dr. Christian Bleis 28 Interaktionskompetenz

Your Project Prof. Dr. Christian Bleis 29 Interaktionskompetenz

The basic idea of this 3rd Step (Controlling + Monitoring) Prof. Dr. Christian Bleis 30 Interaktionskompetenz

Can you imagine different phases of a project? (I) The traditional approach Prof. Dr. Christian Bleis 31 Interaktionskompetenz

6. Make Correction as needed There are three areas where projects most commonly go wrong. The cost of the work is too high. The work isn't completed on time. ( CPM) The work just isn't good enough. ( Ratios, KPI’s) All three of these are your responsibility as project manager -- Cost, Schedule, Quality. You have to follow up early and often if you want to correct problems before its too late. Once a task is finished or has had a cost overrun, it becomes much more difficult to compensate later in the project. Prof. Dr. Christian Bleis Interaktionskompetenz