UNIT-II Project Organization and Scheduling Project Element Five Key Elements are Unique. Projects are unique, one-of-a-kind, never been done before. Start and Stop Date. Projects must have a definite start date and stop date. One Accountable Entity. Unlike operational work, where separate managers are accountable for different parts of the work, projects have only one accountable entity.
Project Element Definitive Prioritization of the TradeOffs When doing the work of projects most people are aware of what has been termed the "triple constraints" of project management.(time, quality, and resource expenditures) Agreement The final element is having agreement between the sponsor and the project manager 2
Types of WBS Process WBS It partitions a large process into smaller & smaller processes. Each process is eventually decomposed into tasks that can be assigned to individuals for accomplishment. Product WBS It partitions a large entity into its components. Each component & interfaces are identified, resulting in a clearer identification of the larger system. Hybrid WBS A WBS that includes both process & product elements of a project into one WBS. Project Life Cycle Project Life Cycle ModelsWaterfall model Prototyping Model Spiral Model 7
Product Life cycle Product development. Product Introduction. Product Growth. Product Maturity. Product Decline. Ways To Organize Personnel Flat Staffing Some of the developers can be assigned to the analysis activities with system analysts. While others may already start other activities such as technology review & trainings. Gradual Staffing The project work is gradually carried out by hiring people as required. It is motivated by saving resources in the early part of the project. 8
What should be the Team Size??? Team Size (n) Positive Impact. Three Members 2. Four Members Even if one member leaves, others continues to work.. Five & Six Members It is an ideal size for a team. Single roles may be given to each member. Members meet face to face. Every member has chance to speak. Negative Impact One member can dominate the other two. One member may perform many roles. Resolving issues like tie during voting can be more time consuming. No negative effects.. Seven Members Effective team size. Team meetings tend to become long. Sub teams formation is necessary. Reviewing the status requires more than half an hour.. Eight & more members Results are usually satisfactory. Too difficult to manage. More competition rather than cooperation of team members. Internal structure starts to break down into sub teams. Stages of Team Development Forming Storming These conflicts are settled & a group feeling should emerge. Performing Various team members try to show their leadership that may result in conflicts. Norming Introduction between team members. Some rules are also setup about behavior. Tasks are decided finally. Adjourning The group is dispersed. 9
Project Scheduling and Control Techniques Gantt Chart Critical Path Method (CPM) Program Evaluation and Review Technique (PERT) Gantt Chart Graph or bar chart with a bar for each project activity that shows passage of time Provides visual display of project schedule 0
History of CPM/PERT Critical Path Method (CPM) E I Du Pont de Nemours & Co. (97) for construction of new chemical plant and maintenance shut-down Deterministic task times Activity-on-node network construction Repetitive nature of jobs Project Evaluation and Review Technique (PERT) U S Navy (98) for the POLARIS missile program Multiple task time estimates (probabilistic nature) Activity-on-arrow network construction Non-repetitive jobs (R & D work) Project Network Network analysis is the general name given to certain specific techniques which can be used for the planning, management and control of projects Use of nodes and arrows Arrows An arrow leads from tail to head directionally Indicate ACTIVITY, a time consuming effort that is required to perform a part of the work. Nodes A node is represented by a circle Indicate EVENT, a point in time where one or more activities start and/or finish. Activity A task or a certain amount of work required in the project Requires time to complete Represented by an arrow Dummy Activity Indicates only precedence relationships Does not require any time of effort
Event Project Network Signals the beginning or ending of an activity Designates a point in time Represented by a circle (node) Network Shows the sequential relationships among activities using nodes and arrows Activity-on-node (AON) nodes represent activities, and arrows show precedence relationships Activity-on-arrow (AOA) arrows represent activities and nodes are events for points in time AOA Project Network for House Lay foundation 2 Design house and obtain financing 2 Dummy 0 Order and receive materials Select paint Build house Finish work 7 Select carpet AON Project Network for House Lay foundations Build house 2 2 Start Finish work 7 Design house and obtain financing Order and receive materials Select carpet Select paint 2
Situations in network diagram B A A must finish before either B or C can start C A C both A and B must finish before C can start B A C B A D B both A and C must finish before either of B or D can start A must finish before B can start Dummy both A and C must finish before D can start C D Network example Illustration of network analysis of a minor redesign of a product and its associated packaging. The key question is: How long will it take to complete this project?
For clarity, this list is kept to a minimum by specifying only immediate relationships, that is relationships involving activities that "occur near to each other in time". Questions to prepare activity network Is this a Start Activity? Is this a Finish Activity? What Activity Precedes this? What Activity Follows this? What Activity is Concurrent with this?
CPM calculation Path Critical Path A connected sequence of activities leading from the starting event to the ending event The longest path (time); determines the project duration Critical Activities All of the activities that make up the critical path Forward Pass Earliest Start Time (ES) earliest time an activity can start ES = maximum EF of immediate predecessors Earliest finish time (EF) earliest time an activity can finish earliest start time plus activity time EF= ES + t Backward Pass Latest Start Time (LS) Latest time an activity can start without delaying critical path time LS= LF - t Latest finish time (LF) latest time an activity can be completed without delaying critical path time LS = minimum LS of immediate predecessors
CPM analysis Draw the CPM network Analyze the paths through the network Determine the float for each activity Compute the activity s float float = LS - ES = LF - EF Find the critical path is that the sequence of activities and events where there is no slack i.e.. Zero slack Float is the maximum amount of time that this activity can be delay in its completion before it becomes a critical activity, i.e., delays completion of the project Longest path through a network Find the project duration is minimum project completion time CPM Example: CPM Network f, h, 9 g, 7 a, i, b, 8 d, j, 2 c, e, 9
CPM Example ES and EF Times f, h, 9 g, 7 a, 0 i, b, 8 0 8 d, j, 2 c, 0 e, 9 CPM Example ES and EF Times f, 2 h, 9 g, 7 a, 0 2 i, b, 8 0 8 c, 0 d, j, 2 8 2 e, 9 7
CPM Example ES and EF Times f, 2 g, 7 a, 0 2 i, 2 29 h, 9 2 0 b, 8 0 8 d, 8 2 c, e, 9 0 j, 2 2 Project s EF = CPM Example LS and LF Times a, 0 b, 8 0 8 c, 0 f, 2 g, 7 2 d, 8 2 i, 2 29 27 h, 9 2 0 2 j, 2 2 2 e, 9 8
CPM Example LS and LF Times a, 0 0 b, 8 0 8 0 8 c, 0 7 2 Float f, 2 9 2 g, 7 2 0 27 d, 8 2 8 2 i, 2 29 27 h, 9 2 0 2 j, 2 2 2 e, 9 2 2 CPM Example a, 0 0 b, 8 0 0 8 0 8 c, 7 0 7 2 f, 2 9 2 g, 7 2 0 27 d, 0 8 2 8 2 h, 9 2 0 2 i, 2 29 27 j, 2 0 2 2 e, 9 7 2 2 9
CPM Example Critical Path f, h, 9 g, 7 a, i, b, 8 d, j, 2 c, e, 9 PERT PERT is based on the assumption that an activity s duration follows a probability distribution instead of being a single value Three time estimates are required to compute the parameters of an activity s duration distribution: pessimistic time (tp ) - the time the activity would take if things did not go well most likely time (tm ) - the consensus best estimate of the activity s duration optimistic time (to ) - the time the activity would take if things did go well t + tm + to Mean (expected time): te = p 2 Variance: Vt = 2 = tp - to 20
PERT analysis Draw the network. Analyze the paths through the network and find the critical path. The length of the critical path is the mean of the project duration probability distribution which is assumed to be normal The standard deviation of the project duration probability distribution is computed by adding the variances of the critical activities (all of the activities that make up the critical path) and taking the square root of that sum Probability computations can now be made using the normal distribution table. Probability computation Determine probability that project is completed within specified time x- Z= where = tp = project mean time = project standard mean time x = (proposed ) specified time 2
PERT Example Immed. Optimistic Most Likely Pessimistic Activity Predec. Time (Hr.) Time (Hr.) Time (Hr.) A - 8 B -. C A D A E A 0.. F B,C G B,C. H E,F 7 I E,F 2 8 J D,H 2. 2.7. K G,I 7 PERT Example PERT Network D A E H J C B I F K G 22
PERT Example Activity A B C D E F G H I J K Expected Time 2 Variance /9 /9 0 /9 / /9 /9 /9 /9 /9 PERT Example Activity ES EF LS LF A B C D E F G H I J K 0 0 9 9 9 7 8 22 2 0 2 9 9 20 8 9 9 20 8 8 2 2 9 8 Slack 0 *critical 0* 9 0* 7 20 0* 0* 2
PERT Example.7 Vpath = VA + VC + VF + VI + VK = /9 + 0 + /9 + + /9 = 2 path =. z = (2-2)/ (2-2)/. = From the Standard Normal Distribution table: P(z <.7) =. +.22 =.72 PROJECT COST 2
Cost consideration in project Project managers may have the option or requirement to crash the project, or accelerate the completion of the project. This is accomplished by reducing the length of the critical path(s). The length of the critical path is reduced by reducing the duration of the activities on the critical path. If each activity requires the expenditure of an amount of money to reduce its duration by one unit of time, then the project manager selects the least cost critical activity, reduces it by one time unit, and traces that change through the remainder of the network. As a result of a reduction in an activity s time, a new critical path may be created. When there is more than one critical path, each of the critical paths must be reduced. If the length of the project needs to be reduced further, the process is repeated. Project Crashing Crashing Crash time an amount of time an activity is reduced Crash cost reducing project time by expending additional resources cost of reducing activity time Goal reduce project duration at minimum cost 2
Activity crashing Crash cost Crashing activity Slope = crash cost per unit time Normal Activity Normal cost Normal time Crash time Activity time Time-Cost Relationship Crashing costs increase as project duration decreases Indirect costs increase as project duration increases Reduce project length as long as crashing costs are less than indirect costs Time-Cost Tradeoff Min total cost = optimal project time Total project cost Indirect cost Direct cost time 2
Project Crashing example 2 8 2 7 2 Time Cost data Activit Norm Norm y al time al cost Rs 2 000 2 8 2000 000 2 0000 00 00 7 00 7000 Crash Crash Allowabl time cost e crash Rs time 7 000 00 7000 9 7000 00 00 22000 070 0 slope 00 00 000 7000 200 200 7000 27
R00 R7000 2 8 2 Project duration = R700 7 2 R00 To.. R000 From.. R200 R200 R00 R7000 2 8 2 R700 7 7 Project duration = Additional cost = R2000 R00 R000 R200 R200 Benefits of CPM/PERT Useful at many stages of project management Mathematically simple Give critical path and slack time Provide project documentation Useful in monitoring costs CPM/PERT can answer the following important questions: How long will the entire project take to be completed? What are the risks involved? Which are the critical activities or tasks in the project which could delay the entire project if they were not completed on time? Is the project on schedule, behind schedule or ahead of schedule? If the project has to be finished earlier than planned, what is the best way to do this at the least cost? 28
Limitations to CPM/PERT Clearly defined, independent and stable activities Specified precedence relationships Over emphasis on critical paths Deterministic CPM model Activity time estimates are subjective and depend on judgment PERT assumes a beta distribution for these time estimates, but the actual distribution may be different PERT consistently underestimates the expected project completion time due to alternate paths becoming critical To overcome the limitation, Monte Carlo simulations can be performed on the network to eliminate the optimistic bias Computer Software for Project Management Microsoft Project (Microsoft Corp.) MacProject (Claris Corp.) PowerProject (ASTA Development Inc.) Primavera Project Planner (Primavera) Project Scheduler (Scitor Corp.) Project Workbench (ABT Corp.) 29
Practice Example A social project manager is faced with a project with the following activities: Activity Description Duratio n w 2w w w Social work team to live in village Social research team to do survey Analyse results of survey Establish mother & child health program Establish rural credit program w Carry out immunization of under fives w Draw network diagram and show the critical path. Calculate project duration. Practice problem Activit y -2 - - 2- - - Description Social work team to live in village Social research team to do survey Analyse results of survey Establish mother & child health program Establish rural credit programme Carry out immunization of under fives Duratio n w 2w w w w w 2 0
Project Scheduling and Tracking What does the customer want to know? Do you understand my needs? Can you design a system to help me? How long will it take? How much will it cost?
Scheduling Principles - Compartmentalization Interdependency the product and process must be decomposed into a manageable number of activities and tasks tasks that can be completed in parallel must be separated from those that must completed serially Time allocation every task has start and completion dates that take the task interdependencies into account Scheduling Principles - 2 Effort validation project manager must ensure that on any given day there are enough staff members assigned to completed the tasks within the time estimated in the project plan Defined Responsibilities every scheduled task needs to be assigned to a specific team member 2
Scheduling Principles - Defined outcomes every task in the schedule needs to have a defined outcome (usually a work product or deliverable) Defined milestones a milestone is accomplished when one or more work products from an engineering task have passed quality review Total Float Time
QUESTIONS-
What do you mean by a dummy activity? Why it is used in networking?
Pert Question- Pert Question 7