Project Scheduling and Time Management PDF

Chapter three 3. Project Scheduling 3.1 Time Management 1 3.1.1. Importance of project schedules  Project Time Management includes the processes required to ensure timely completion of the project. 2 Key Terms  Early Start (ES)- The earliest that an activity can star...

Chapter three 3. Project Scheduling 3.1 Time Management 1 3.1.1. Importance of project schedules  Project Time Management includes the processes required to ensure timely completion of the project. 2 Key Terms  Early Start (ES)- The earliest that an activity can start.  Early Finish (EF)- The earliest that an activity can possibly finish.  Late start (LS)- The latest that an activity can start and not impact project completion.  Late Finish (LF)- The latest that an activity can be completed without impacting the project completion.  Float- The number of days that an event or lag can be delayed or extended without impacting the completion of the project. 3 Con…  Forward Pass- A calculation starting with the first activity and ending with the last activity performed to find the early dates & the duration of a specific project.  Backward Pass- A scheduling calculation done to determine the activity late dates. This calculation begins with the last activity and project duration and culminates(ending) with the first activity.  Critical Path- Longest continuous chain of activities through the network schedule that establishes the minimum overall project duration. 4  Cont…  Activity – a chunk of work that is part of the project; an activity may be broken down into multiple sub activities  Event – a significant point in time during the project, such as a milestone event; an event could be the time at which an activity is completed or the time at which related concurrent activities have all completed  Dummy Activity – an artificial activity with zero time duration that only shows a precedence relationship among activities 5 Main processes of Project time management The following processes are used in developing project time scheduling: 1.Activity Definition: identifying the specific schedule activities that need to be performed to produce the various project deliverables 2.Activity Sequencing: identifying and documenting dependencies among schedule activities 3.Activity Resource Estimating: estimating the type and quantities of resources required to perform each schedule activity 4.Activity Duration Estimating: estimating the number of work periods that will be needed to complete individual schedule activities 5.Schedule Development: analyzing activity sequences, durations, resource requirements, and schedule constraints to create the project schedule 6.Schedule Control: controlling changes to the project schedule Note:- These processes interact with each other and with the processes in the other knowledge areas as well. 6  1. Activity definition  Identifying and documenting the work that is planned to be performed  Project work packages are planned (decomposed) into smaller components called schedule activities to provide a basis for estimating, scheduling, executing, and monitoring and controlling the project work 7 Activity definition: Input, Tools & techniques, and Output 8 2. Activity sequencing  Activity sequencing involves identifying and documenting the logical relationships among schedule activities  Sequencing can be performed by using project management software or by using manual techniques 12 Activity sequencing: Tools & Techniques Project Network Diagrams(PND) Network diagrams show the precedence relationships among activities It’s easier to understand these relationships graphically Network diagrams help to understand the flow of work in a project Network diagrams are a useful tool for project planning and control, as well as for scheduling One (perhaps exaggerated) claim is that the network represents ¾ of the planning process 13  Versions of Network Diagrams 1. Activity-on-Arrow (AOA) networks  also called Arrow Diagramming Method (ADM)  simpler for projects with many dependencies  emphasizes events; milestones can be easily flagged  sometimes requires dummy activities  uses arrows to represent activities and connects them at nodes to show their dependencies  ADM uses only finish-to-start dependencies and can require the use of “dummy” relationships called dummy activities, which are shown as dashed lines, to define all logical relationships correctly 14 Examples as follow:- c e b g d f k k or j j Dashed lines are called dummy activities Activity Predecessor m r m _ _ n r m, n n s s n 15 2. Precedence Diagramming Method (PDM) easierto draw for simple projects emphasizes activities no dummy activities. Known as activity on-node (AON) 16  Cont…  Includes four types of dependencies or precedence relationships: 1. Finish-to-Start: the initiation of the successor activity depends upon the completion of the predecessor activity 2. Finish-to-Finish: the completion of the successor activity depends upon the completion of the predecessor activity 3. Start-to-Start: the initiation of the successor activity depends upon the initiation of the predecessor activity 4. Start-to-Finish: the completion of the successor activity depends upon the initiation of the predecessor activity 17 Cont… 18  c=3 a=4 g=1 j=6 d=2 Start Finish e=6 h=4 b=3 k=1 f=4 i=5 19 Activity resource estimation  Estimating schedule activity resources involves determining what resources (persons, equipment, or materiel) and what quantities of each resource will be used, and when each resource will be available to perform project activities 22 3. Activity duration estimate  The process of estimating schedule activity durations uses information on schedule activity scope of work, required resource types, estimated resource quantities, and resource calendars with resource availabilities  requires that the amount of work effort required to complete the schedule activity is estimated  Estimating the number of work periods required to complete a schedule activity can require consideration of elapsed time as a requirement related to a specific type of work 24 Activity duration estimate: Tools & techniques 1. Analogous Estimating: estimating means using the actual duration of a previous, similar schedule activity as the basis for estimating the duration of a future schedule activity 2. Parametric Estimating: estimating the basis for activity durations can be quantitatively determined by multiplying the quantity of work to be performed by the productivity rate 26 4. Schedule development Project schedule development, an iterative process, determines planned start and finish dates for project activities 28 Schedule development: tools and techniques 1. Schedule Network Analysis: It employs a schedule model and various analytical techniques, such as critical path method, critical chain method, what-if analysis, and resource leveling to calculate the early and late start and finish dates, and scheduled start and finish dates for the uncompleted portions of project schedule activities 2. Critical Path Method(CPM) steps:  The critical path is composed of a continuous chain of activities through the network schedule with zero total float.  All activities on the critical path must start and finish on the planned early start and finish times. 29 Example Under Network Diagram 31  Example others forward path EF= ES+DURATION f 32 Backward path LS= LF-DURATION 33 Con… 34  6. Schedule control  Schedule control is concerned with:  Determining the current status of the project schedule  Influencing the factors that create schedule changes  Determining that the project schedule has changed  Managing the actual changes as they occur 38  The Work Breakdown Structure (WBS)  Used as a basis for a number of processes in particular to produce the subsidiary plans of the Project Management Plan. WB  The WBS is a deliverable-oriented hierarchy of S decomposed project components that organises and defines the total scope of the project. The WBS is a representation of the detailed project scope statement that specifies the work to be accomplished by the project.  The elements comprising the WBS assist the stakeholders in viewing the end product of the project.  The work at the lowest-level WBS component is estimated, scheduled, and tracked. 39  Developing the WBS  Divide the total work of the project into major groups... ...then subdivide these groups into WB tasks... S ...then divide these tasks into sub-tasks  Subtasks should be small enough to permit adequate control and visibility  But avoid excess bureaucracy! 40 Example: Time-Based WBS 41 Ch3-Assignment Task Pred. Duration Pred. Duration a -- 4 g c, d 1 b -- 3 h e 4 c a 3 i f 5 d a 2 j e,g 6 e b 6 k h,i 1 f b 4 1. Find the network diagram? For each task: 1. Compute forward path ES, EF ? 2. Backward path LF, LS ? 3. Find the Slack TIME ? 42