Project Planning & CPM Scheduling using MS Project APWA NorCal 2018 Annual Conference
What is Planning? Planning: A determination of the what, how, where and by whom ; the tasks that need to be completed to finish any project washing the car grocery shopping laying drainage pipe building a skyscraper
What is a schedule? Schedule: The when of planning. The planning information is necessary to organize, orchestrate and develop a schedule.
Gantt Chart or Bar Chart A simple presentation that show how major work activities are scheduled Primary Advantages Grind Exist. Striping and Conforms Roadway Overlay simple graphic representation to allow quick and easy Activity Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 9 Day 10 insight to schedule information no extensive training is required to learn how to extract information from them Sweep and Roadway Prep AC Overlay Paving Shows operations and the time utilized by each operation. Can show the scheduled vs. actual progress Roller Compaction AC Set/Cure Place Striping
Work Breakdown Structure (WBS) Work Breakdown Structure (WBS) a systematic way of describing the component pieces of a project schedule. That is, the work is broken down to systems (i.e. Plumbing, Mechanical, Sitework, etc.) and the systems are further broken down into greater detail.
WBS (cont. d) Created from the top down approach, NOT the bottom up Breakdown of the project, i.e. Project task to subtask to sub-subtask, etc. Level of detail will be determined by the complexity and schedule needs WBS breaks project down to manageable pieces rather than one grandiose whole Requires input from various parties: PM, Supt., Subs, Suppliers, etc.
WBS (cont. d) NO SINGLE CORRECT WBS its development is directly dependent on who is developing the WBS. Logic may be similar but inherently there will be nuances. WBS is NOT a schedule, rather a breakdown of the various activities Similar to an outline for a paper or book
AC Overlay WBS AC Overlay WBS.xlsx
Schedule Definitions Resources Labor, materials, equipment and time Activity Duration time required to perform a specified quantity of work/productivity rate Critical Path A continuous chain of activities with the longest duration; it dictates the project completion
Definitions (cont. d) Early Start The earliest time that an activity can start Early Finish The earliest time that an activity can finish Late Start The latest time that an activity can start and not prolong the project Late Finish The latest time that an activity can finish and not prolong the project
Definitions (cont. d) Float The amount of free time or time difference between the calculated duration of the activity chain and the critical path is call float. It allows an activity to start later that its early start and not delay the project. Can be classified as free or total float Total Float The measure of time in starting and completing an activity; usually measured in days Free Float Also referred to as activity float because, unlike total float, free float is the property of the activity and not the network path. Free float is the amount of time the start of an activity may be delayed without delaying the start of successor activity. Lag The amount of time that exists between the early finish of an activity and the early start of a specified succeeding activity
Definitions (cont. d) Activities have 5 specific characteristics: Consumes time Consumes resources It has definable start and finish It is assignable It is measurable Construction projects are made up of numerous individual activities that must be accomplished to finish the project.
Definitions (cont. d) Concurrent Activities Activities that are logically independent of one another and can be performed at the same time Predecessor Activities An activity that must be completed prior to the next activity starting. Successor Activities An activity that cannot start until the preceding activity is completed.
Definitions (cont. d) Milestones - The Schedule has a single activity defining the start and a single activity defining the finish of the schedule Note: Activities consume time, Milestones simply occur at a point in time (i.e. Zero duration)
Definitions (cont. d) Relationship Types: Finish to Start (FS) the predecessor activity finishes before the successor activity starts Start to Start (SS) the predecessor activity and successor activity start at the same time Finish to Finish (FF) the predecessor activity and successor activity finish at the same time Start to Finish (SF)** typically used with a lag, the predecessor activity finishes when the successor activity starts ** - Note that this relationship is available but not widely used.
Reasons for Planning and Scheduling in Construction Contract requirement Provides proof to the Owner that the Contractor has thought the project through Provides the Owner the tool by which to hold the Contractor accountable Provides the Contractor the tool by which to hold the Owner accountable
Reasons for Planning and Scheduling in Construction Aids in identifying potential problems Available labor Available equipment Material procurement lead time, etc. Site Logistics Too many activities in one area Working hours Local City/State Requirements Union Requirements Environmental Requirements
Developing a Network Model The development of the network model is perhaps the most important step in using a network as a scheduling tool. Fundamental concept: - The network represents a time-oriented model of a system, not unlike a physical scale model of a project. NOTE: Scheduling is a mathematical analysis based on duration and dates.
Steps in Building a Network Model 1. Define Activities 2. Order Activities 3. Establish activity relationships and draw a network diagram 4. Determine quantities and assign durations to activities 5. Assign resources and costs, if applicable 6. Calculate early and late start/finish times 7. Compute float values and identify the critical path 8. Schedule activity start/finish times
Network Model development key points: Typically an iterative process Should continue throughout the life of the project Must be updated to reflect changes by Owner, Site Conditions, etc. sequence must be reflect the changes NOTE: Step 5 Resources & Costs is only utilized when resources and cash flow need to be addressed. This step is not utilized by many schedulers The model should be updated to reflect the actual construction activities is it is to be a useful construction tool.
Defining Activities Anything that must be accomplished in order for the project to be completed may warrant inclusion in the network Activities are regardless of: Who is responsible What resources are required Costs Duration
Primary Activity Types Production/Construction relate directly to the physical effort of creating the project Excavate/Place/Backfill Trench Frame Interior Walls Plumb 1st Floor Water Lines
Primary Activity Types (cont. d) Procurement relate to arranging for the acquisition of materials, money, equipment and manpower Order Signal Standards Obtain Remodeling Loan Execute Concrete Purchase Order
Primary Activity Types (cont. d) Management the support and administrative tasks that often directly impact the project schedule Submit Rebar Shop Drawings Submit Inspection Reports Approve SWPPP
Ordering Activities Based on the timing of certain activities relative to other activities. Guide to ordering: Which activities must precede it? Which activities must follow it? Which activities can be concurrent with it?
Ordering Activities (cont. d) Immediately Preceding Activities (IPA) identify which activities must precede the subsequent. When this is performed, all subsequent activities will have been identified and concurrent activities will show themselves, unless there are constraints. Constraints Dictate the order in which activities are performed
Types of Constraints: Physical relate to the physical process of construction, i.e. dig trench before placing pipe Resource preclude activities from occurring at the same time as a result of insufficient resources, i.e. only 1 piece of equipment, finite amount of material delivered, etc. Safety preclude unsafe conditions from occurring Financial preclude from too large or small of financial obligation
Types of Constraints (cont. d) Environmental preclude work from being performed until certain environmental issues are addressed Management typically uncategorized constraints, i.e. holidays, training requirements, etc. Contractual Owner imposed constraints, i.e. time of completion, impacting adjacent operations, etc. Regulatory Local, State & Federal regulations, i.e. permits, working hours, etc.
Assigning Duration to Activities Duration estimated time required to complete an activity Typical unit of measure is days Determination is more of an art form than science Frequently directly related to labor cost estimates
Assigning Duration to Activities (cont. d) Major factor: productivity rate which can be influenced by the following: Labor skill ( A team vs. C team) Weather (hot/cold/windy/wet/etc.) Working Conditions (limited physical constraints) Quantity of Work (learning curve)
Determining Activity Durations - Estimating Accurate Estimate depends on: The accuracy of the quantity take-off Includes the cost of: Labor, Equipment and Material Overhead & Profit The Project Schedule either directly affects OR is directly affected by each of these components!
Other Estimate/Schedule Factors Contract Specifications Dates or durations / Specific Milestones Working hours Required access/impact to the area Regulations Permits Local Agencies Environmental
Units of Time Working Days vs. Calendar Days Rule of Thumb: Working days are typically associated with project that may be affected by weather Concrete Cure, Administration Tasks, etc. Weekends & Holidays Weather Delays Holidays
Progress Schedule Like the Plans and Specifications, the Project Schedule is an integral tool for the Contractor and Owner regarding the status of the Project, it should be updated and maintained regularly
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