Ch. 13 Project Planning and Scheduling
what is a project
A temporary endeavor undertaken to create a unique product, service, or result.
examples of projects
Building Construction bridge construction aircraft carrier R&D project Audit etc.
notation used to calculate start and finish times
ES(a)=early start of activity (constrained by predecessors)- pessimistic EF(a)=early finish of activity (constrained by early start time)- optimistic LS(a)=late start of activity (Constrained by late finish time)-pessimistic LF(a)=late finish of activity (without delaying successors)-optimistic
what is PMI
Project Management Institute
what is RFP
Request for Proposal
why do we take the max EF of all predecessors to each activity for its early start time
activity cannot start until all its predecessors are finished. even one predecessor that isn't finished can hold up the early start of the next activity, leading to the max EF all predecessors that lead to the formula.
distinguish the advantage and disadvantages of a network over a gantt chart for project scheduling
advantage of network over gantt is that precedence relationships in network scheduling are shown explicitly on the network permitting the relations when the schedule is developed. gantt charts precedence relations must be kept in the scheduler's head and during complex projects that is not easily done.
what is performance
characteristics of the P/S by meeting measures of outcome success for the project also may require tradeoffs with cost and schedule
what is schedule
completion date and intermediate milestones manager and team's control schedule to meet dates budget and schedule usually conflict meaning there is a trade-off between time and cost
compare and contrast the use of constant time and CPM networks
constant time is adequate for cases when activity times are constant or nearly so CPM methods by contrast should be used when activity times are fairly constant but can be reduced by spending more money. CPM applies in cases like construction projects, installation equipment and plant start-up and shutdown. more advanced network methods include PERT, generalized networks, resource constrained networks and project management based on the theory of constraints.
objectives and tradeoffs of projects
cost, time and quality (performance) cost & time - quality suffers time & quality - cost suffers cost & quality - time suffers stay on schedule --> stay within budget --> meet specifications --> stay on schedule schedule and costs are the big two activities
type in project, duration and predecessors in project libre =
creates a gantt chart for you red=critical blue=not critical makes schedule with ES EF LF LS
what's the significance of the critical path and slack
critical path is the longest path in a network slack is the mathematical difference between ES and LS or EF and LF all activities on the critical path must be carefully monitored as if they slip the project and completion date will slip by a like amount
any delay on critical path
delays the project (unless 'corrective actions' are taken)
check computations by
determining whether ES=LS and EF=LF for activity A, the first one in the network
Scheduling Activities and Decisions
develop a detailed work-breakdown structure estimated time required for each task sequence tasks in proper order develop a start/stop time for each task develop a detailed budget for each task assign tasks to people, subcontractors, etc.
critical path method (CPM)
developed to start-up/shutdown plants requires single time estimate for each activity looks at time/cost tradeoffs like normal or crash times/costs uses a time-cost trade off rather than a constant time
what is cost
direct and allocated costs assigned to the project its the manager and team's job to control the costs typically covering labor, materials and support services
ES
early start - earliest that an activity can start based on the early completion of all predecessor activities
time cost relationship with CPM
figure out where the crash is by find critical path which activity is cheapest to buy time from make time cost relationship
closing activities and decisions
finish all work close contract pay all account payable turn project over to owners reassign personnel and equipment
what are the two types of scheduling methods
gantt chart network method
what is a network method
graphs or networks to show precedence relations through a more complex, difficult to understand and costly software compared to gantt charts
what is a work-breakdown structure
heart and soul of project management how you will meet request of the work being done final deliverables deliverables along the way work packages **basis for planning, scheduling, budgeting and controlling the project can use a bottom up approach by rolling up work package to the final deliverable
a savvy project managers knows
how to propose the best time and cost to get the deal
planning activities and decisions
identify project customer establish end P/S set objectives estimate total resources and time required decide on form of project organization make key personnel appointments define major tasks required establish a budget
the body of knowledge PMI has required for certification as a project manager
integration scope time management costs quality management HR communications risk procurement
slack
time a path may be delayed without delaying the project paths not on the critical path have slack =LS-ES =LF-EF
problem with crashing and time
two people painting a closet= no enough room and more cost for more time to finish two people painting a house in 10 days, adding the extra person brings the cost up but time down
characteristics of a project
unique item or event- often a single unit begin and ends - not ongoing often done on-site resources are brought to the project
an example of bottom up budgeting
wedding includes rehearsal, ceremony, reception and trip work packages between each add to the final deliverable
calculating ES, EF, LS, LF completion time in forward pass-- logic of calculation formulas:
· ES(a)=0 for the starting activities · EF(a)=ES(a)+t(a)* · ES(a)= Max (the bigger one) [EF(all predecessors of a)] · Project completion= Max[EF(all ending activities)]
calculating ES, EF, LS, LF completion time in backward pass
· LF(a)= Min [LS(all successors of a)] · LS(a)= LF(a)-t(a)*
who defined project this way in the card above
project management institute
planning for the project is required before
scheduling begins and control is required after the schedule is developed
activity on node (AON) network
shows each of the four activities as a node in the diagram and arrows indicate the precedence relationships between each
gantt chart
shows the time you give to each work package
project libre
similar to microsoft projects
project network
solved using normal time and costs for all activities if completion is too long, the project can be completed in less time at a greater cost by crashing for certain activities any completion time less than normal time, many network possibilities exist each at different total cost evaluated by linear programming problems
selecting project scheduling method makes a conscious trade-off between
sophisticated and cost
crashing
spending money to come in early - early enough =make money on the deal
what is a gantt chart
a bar chart that shows the visual and linear direction of project tasks useful for tracking deadlines and monitoring a project's progress, as well as for planning and scheduling tasks
describe the four activities includes in project management
planning- major project objectives, resources, organization and people scheduling- specifies project plan in more detail-work breakdowns control- cross-functional team monitors each activity as performed closing- formal ending of the project
LS
late state- latest finish an activity can have and still ensure the project be completed on time
the critical path=
longest path in the network with 0 slack!
critical path
longest path through the network with no slack
constant -time networks
look at scheduling work packages activities assumed to be constant and represented by nodes as the arrows show precedence relationship
crash activities
make more or multiple critical paths if you don't buy time from all CP you will loose the deal
explain the nature of tradeoffs among the three objective of project management
managers andd team's control the cost, schedule and performance of a project, but may have to trade off one for the other. i.e., in a movie if the picture isn't meeting performance expectations, additional shots or scripts may be required causing cost and schedules to change
control activities and decisions
monitor actual time, cost and performance compare planned to actual figures determine corrective action if needed evaluate alternative corrective action take appropriate corrective action
contrast and compare CPM and PERT as project-scheduling techniques
o CPM methods are used when activity times are fairly constant but can be reduced by spending more money, like construction projects, installation of equipment, and plant start-up and shutdown. o More advanced network methods include PERT (Program evaluation review technique) - Probabilist times based on the theory of constraints through graphical representation of the project's time line by breaking down each individual tasks of a project for analysis.
sequence of management decisions required in all projects
o Control --> planning (to do list) --> scheduling --> closing (completion)
management significance of finding the critical path through a network
o In managing a project, all activities on the critical path must be monitored because if any activities slip (takes more time than planned) the completion date of the project will slip by a like amount. helps to determine expected project completion time, bottlenecks and where management could crash the project to speed it up if need be
how precisely, does project scheduling differ from the scheduling of ongoing operations?
o Projects have a beginning and an end - not ongoing events. Project completion date and intermediate milestones are established at the outset of project scheduling, the schedule must stay in control to meet established dates. o Ongoing operations don't have an end date and do not have to stay within a controlled time series.
use of project management concepts
o Scheduling is only part of a complete approach to project management o Trade-off between sophistication and cost of methods o Choice between constant-time, CPM or more advanced techniques o Choice of project management software packages § E.g. Microsoft project
why are forward pass and backward pass needed to produce a project schedule?
o diagram. o Backward pass calculates the late start and late finish times. o Check computations by determining whether the ES=LS and EF=LF for activity A, the first one in the network. After going backward you should always end up with the same ES and EF times that you started with when going forward. o Forward pass is used to find the critical path and backward pass determines if there is any slack in the activity.
example of a failed project
olympics in Atlanta, building finished to house athletes leaned a few degrees after completion and therefore condemned at the final check
closing activities types
perpetual normal failed project