COMMERCE 2OC3 Study Guide - Midterm Guide: Randomness, Forward Pass, Gantt Chart
5 Jun 2018
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Department
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Professor
Projects are a set of related tasks or activities, directed towards some major output or objective.
Hamilton B-Line, a 14 km LRT between McMaster University and Eastegate Square, expected to open
2024 but facing delays
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ICE Condominiums, two high rise condominiums scheduled to open March 2014, inaugurated November
2017 but still unfinished
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TTC Subway Expansion, expected completion 2015, faced delays until 2017 (utility issues, fatal accidents,
contractor relationship strains, abnormally large number of rework orders placed by TTC)
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Union Station, expected completion 2015, still ongoing as a result of incomplete proposals, questionable
billing, missed deadlines, lack of cost controls, insufficient recordkeeping
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Examples include:
Activities take longer, cost more, or must be completed in a different order than expected
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E.g. IT systems under $1M have a 75% chance of on-time completion, dropping to 40-50% at $2-3M, and
under 10% over $10M
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Why Projects Fail
Includes work breakdown structure (WBS), with level 1 detailing the project, 2 detailing major
tasks, 3 detailing subtasks, 5 activities to be completed
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Project planning before project begins
1.
Project scheduling as project begins
2.
Project control during project
3.
Phases of Project Management
Visualizing Project Schedules
Do not reveal dependencies among tasks
○
Gantt chart with columns representing time
periods and rows representing activities and the
periods performed in (bars)
Clearly define each activity and their
relationships
1.
Draw network model representing
sequence of activities using nodes with
arrows representing flow of
predecessor activities; denoted by
activity-on-node (AON) network
(activity-on-arrow, AOA is also used)
2.
Compute earliest and latest start and
finish times, critical path analysis
3.
Project evaluation and review technique (PERT)
developed for construction of Polaris
submarine (USA) used in large projects, can
handle uncertain activity times and contain
CPM
•
CPM/PERT rely on network representations
that can indicate bottlenecks, durations, and
delays
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Use forward pass, then backward pass to
calculate ES, EF, LS, and LF
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Latest start time (LS), latest finish time (LF) are the latest times an activity can start
and finish so as not to delay the completion time of the entire project
For all nodes with no predecessor,
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For all nodes,
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For nodes with predecessors
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Forward pass:
For the last nodes with no successors
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For all nodes,
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For nodes with successors
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Backward pass:
Useful for scheduling and controlling large projects, are widely applicable
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Tedious but mathematically straightforward
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Graphical networks aid perception of relationships and visually represent activities
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Critical path and slack times pinpoint activities that need to be watched
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Monitoring schedules, costs, and when things don't go to plan
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Advantages of PERT/CPM include:
Slack Time, Idle Time, Critical Path
Project Management
January 11, 2018
2:33 PM
Operations Management Page 1
Document Summary
Projects are a set of related tasks or activities, directed towards some major output or objective. Hamilton b-line, a 14 km lrt between mcmaster university and eastegate square, expected to open. Ice condominiums, two high rise condominiums scheduled to open march 2014, inaugurated november. Ttc subway expansion, expected completion 2015, faced delays until 2017 (utility issues, fatal accidents, contractor relationship strains, abnormally large number of rework orders placed by ttc) Union station, expected completion 2015, still ongoing as a result of incomplete proposals, questionable billing, missed deadlines, lack of cost controls, insufficient recordkeeping. Activities take longer, cost more, or must be completed in a different order than expected. It systems under m have a 75% chance of on-time completion, dropping to 40-50% at -3m, and under 10% over m. Includes work breakdown structure (wbs), with level 1 detailing the project, 2 detailing major tasks, 3 detailing subtasks, 5 activities to be completed.
