Estimating Exam 2
RSMeans Productivity Terminology
"Crew" • Grouping of laborers (across trades and skill levels) in a functional material installation team • Power equipment commonly used for the material installation task "Daily Output" • Measure of daily production (completed work), in stated units • Specific to stated "crew" composition • Represents work in an 8‐hr day, working in daylight, and in temperate conditions "Labor‐Hours" • Amount of labor (hours) required to perform one unit of work • Labor‐hours is a metric independent of crew size; but, a change in crew size will correspondingly change the daily output
Ways to Address Duration Uncertainty
"Three‐point" calculation (optimistic, pessimistic, most likely values) as a weighted average for the potential duration range Inserting "cushion" time (i.e. additional duration) to address uncertainty about a task's required duration "Cushion" time is added in one of two ways: - Integrated (i.e. embedded) in the task duration value • Lengthens a task's total duration • Delays the task's completion date • May delay the project's finish date (if activity is on or impacts the critical path) • Improves probability of completing task within the stated duration - "Buffer" separate (i.e. decoupled) from task duration value: • Additional time "assigned" to a risky task (appears as separate from task duration values in the schedule) • With improved information at schedule updating, the buffer time can be reduced, eliminated, or possibly reassigned
Detailed (Unit Price Estimate)
- During late design development and procurement phases - Based on the most detailed design information (completed documents or work packages) - Engages many entities (i.e. subs, suppliers, equipment manufacturers, etc.), and expensive to develop - Involves scoping, quantifying, and pricing each component of the proposed construction - Benefits include: • Most flexible (customizable) of all methods, and therefore, most accurate • Establishes the project's "contract cost", to establish the cost of change orders during construction
Total float equals
- Late start time minus early start time - Late finish time minus early finish time - Late finish time minus (early start plus duration)
CSI MasterFormat 2016
- RSMeans' unit price data is organized according to this system (as well as project written specifications) - Organized by product or material (not by major project element as in UNIFORMAT II)
Sales Tax does not apply to...
-General Requirements (conditions) and overhead -subtotal of GC self-performed work and subcontractor costs
The quantities calculated in unit price estimating must be adjusted for waste that will likely occur due to:
-Inefficiencies in field fabrication methods -Spillage during field activities.
"Free" Float
-The amount of time that an activity can be delayed without delaying any succeeding activity -Can only occur when two, or more, activities share the same successor Free Float = ESEarliest Succesor - EFActivity Evaluated
The amount of profit charged on a project is a factor of...
-The extent of risk -The amount of competition expected -The expected outcome of the project
Duration - Parametric Technique Example Solution Steps
1. Define the work activity 2. Quantify the work activity (material and # units) 3. Locate productivity data 4. Calculate duration estimate
Steps for Diagraming Network Logic
1. Prepare a WBS to develop an accounting of all required activities (i.e. work tasks) 2. Establish "immediate" relationships for each activity, and preserve other data a) Predecessor - the "before" activity (can be more than one) b) Successor - the "after" activity (can be more than one) c) Activity‐related resource needs and constraints (i.e. to identify potential bottlenecks, such as elevator use) 3. Create a network logic diagram by assembling activities into a logical sequence (i.e. "connecting the dots"); best performed in a team environment a) Beginning toward end (traditional method); by an experienced individual making best guess of a plan b) End toward beginning (i.e., "pull planning", a "lean" concept); team approach with project‐specific stakeholders involved, working collaboratively to deliver project with reduced schedule and cost 4. Always originate the network with a single initial (or "begin") activity, and end with a single terminal ("end") activity 5. Iterative process (there will be changes), may include backward arrows, logic loops, and inserted activities 6. Review and revise
Detailed Estimating - Two Basic Steps
1. Quantification • Scoping what materials and items of work • Calculating quantities of the materials and items of work 2. Pricing • Identifying material costs and costs of installation • Application of unit prices to the measured quantities
Relative Effort and Accuracy of Estimates (Within %)
20% - Order of Magnitudes Estimate 15% - SF and CF estimate 10% - System Estimate 5% - Unit Price Estimate (takes about 3 weeks)
Detailed Estimating General Procedure
A. Obtain, and thoroughly review, contract documents • Drawings ("plans") • Written Specifications ("technical specifications") • Supplemental information and special provisions • Addenda B. Perform a site analysis • Site setting impacts (regional and project‐specific), including subsurface conditions • Typically this information is not conveyed on drawings, and can have major cost implications C. Scope and price self‐performed ("in‐house") portions of the project work D. Contact subcontractors and material/manufacturer/equipment vendors • Communicate their scope ("work package") and request pricing • Receive and review their cost submittals (including the scope they priced) E. Subtotal self‐performed and subcontractor costs (separately), and apply "recurring" cost components • General requirements • Indirect costs • Profit • Contingency • Adjustments (location and/or time)
Quantity of Work Units ("The Activity") x Installation Unit Cost = ...
Activity Cost
Labor pricing requires knowledge of:
Activity duration and hourly wage
Duration - "Built" Crew Example
Adjust RSMeans' daily output (productivity) to reflect the "built" crew's daily output 1. Itemize the "built" crew's labor resource by trade and level (structural steel foreman, structural steel laborer, welder, etc.) 2. Determine the "built" crew's daily total labor hours (# laborers x 8 hours/laborer‐day) 3. Locate RSMeans' "labor‐hour" value for the specific material to be installed 4. Calculate the "built" crew's daily output (i.e. productivity) 5. Estimate duration of installation, as performed by the "built" crew
"Gantt Schedule"
Advantages: • Easy to read (no training required) • Good communication tool • Easy to update Disadvantages: • Activities "rolled‐up" into broad scopes • Does not show inter‐relationships (i.e. dependencies) of activities • Cannot resolve impacts of delays (e.g., deliveries, work installed, weather, etc.) • Limited usefulness during construction phase
"Network" Schedule
Advantages: • Visual layout (flow chart) of all work activities in a project • Depicts activity sequencing and inter‐dependencies (i.e., "job plan") • Contains activity duration and start/finish dates • Identifies the most critical activities that should not be delayed (i.e. "critical path") • Establishes priorities for allocating resources (labor, equipment, materials, and space) to operations • Helps project managers (PMs) stay on plan Disadvantages: • Requires training to interpret • Requires detailed project information • Consumes considerable effort and expense to develop (weeks to months)
What is Scheduling?
Any project is made up of components and activities that need to be integrated (inter‐dependencies). These components and activities need to occur in sequence to achieve the objective(s). Scheduling is the process of... • Identifying project components and activities • Determining inter‐dependencies between the components and activities • Organizing the components and activities into a logical sequence • Assigning duration and start/finish dates to each activity • Estimating the overall project duration
Two Most Common Schedule Formats
Bar Chart (Gantt chart) • Display of major activities as bars overlaid on a calendar Network Analysis (critical path method ‐ CPM) • Time analysis of a network of activities that outlines the steps needed to complete a project. Type used, and extent of detail, is a function of • Project complexity • Project delivery method • Contract requirements • Point in project timeline (i.e., pre‐construction vs. construction phase)
Duration - Data Sources
Based on estimated production rates • Proprietary historical data (company database) • Purchased data (i.e. RSMeans, Walker, trade publications, etc.); "average" data Subcontractors and vendors • Understanding of demands on their resources from other concurrent projects • Realistic schedule to manufacture and deliver project‐specific items Experienced superintendents and crew leaders Confirm production rate data units • Quantity per area, volume, length, weight? • Quantity per hour or day? • Is a "day" 8 or 10 hours?
Working Day Numbering Definition
Day numbering: • Assigned to each activity's start and finish times • Tells us if an activity starts (or finishes) at beginning or end of Day X • Based on whether project start is considered as Day 0 or 1 (all subsequent day numbering refers back to it)
A forward pass is used to determine...
Early start and early finish times
Three‐Point Concept for Uncertainty
Estimator determines three different duration estimates: • Optimistic - lower bound (shortest) • Pessimistic - upper bound (longest) • "Most Likely" - average value when performed many times Set a confidence level for lower (optimistic) and upper (pessimistic) bounds (e.g. say 90%, as values that are exceeded only 1 in 10 projects), and assign duration values in that context. Select a probability distribution: • Triangular; average skewed toward outlier. • Beta; value tighter to "most likely". Good option when uncertainty about the activity; but don't be fooled by fancy statistics if input data (i.e., O, M, and P) are unreliable
Equipment costs are figured by totaling the cost of maintenance, fuel, and operator.
False
The maximum amount of time that an activity can be delayed without extending the completion time of the overall project is called:
Float
"Float" and "Critical Path" relationship
Float is the difference in time (days) between an activity's late and early start (or late and early finish); also called "slack". Critical Path is the head‐to‐tail path of activities through the network (start to finish) for which each activity has zero float time 13. Critical path (CP) establishes the optimum sequence and duration of operations between the first and last events
Why Schedules are Useful
For Constructor: • Predicting whether the required completion date is attainable • Planning (coordination of subs, equipment, and material delivery) • Monitoring (actual vs. planned production rates, overall progress status, change order/claim support) • Controlling (which adjustments to maintain cost and schedule objectives). For Subs and Suppliers - to know when labor and materials are needed. For Owner - cash flow timing (i.e. financing). For Facility User - planning of start‐up and occupancy. Communication is the major purpose of a schedule
Network Computation Processes
Forward Pass (Step 1) - Earliest Timing • How early can an activity start? (early start - ES) • How early can an activity finish? (early finish - EF) • How early can the project finish? (expected time - ET) Backward Pass (Step 2) - Latest Timing • How late can an activity start? (late start - LS) • How late can an activity finish? (late finish - LF) • Which activities represent the critical path?
Overhead costs associated with which of the following components has the highest relative (percentage) cost? (General requirements (field overhead), Home office overhead, or Labor burden)
Labor burden
Sales tax is applies to...
Material and Equipment Costs
Certain key events are called...
Milestones
Ways to Shorten an Activity Duration
Narrow the activity scope, but...may be too disruptive since WBS is already established at point of scheduling. Increase the amount or number of resources assigned (i.e. labor and/or equipment). Increase efficiency of the work, such as: - Change labor skill level - Use power equipment where possible - Automate the process (modular/prefabrication) where possible
Detailed Estimating
Perform a "quantity takeoff" (QTO) to identify and quantify all component materials and activities in the project (Step 1). Group related materials and activities into logical "work packages" to assist with • Coordination of trades/subs • Estimate development • Schedule development Assign pricing (Step 2) to each • Component material • Activity • Work package (grouping of materials/activities)
Cost Line Items vs. Schedule Activity
Possible Cost Line Items for Steel Framing: -Deliver and set steel columns, girders, and beams -Provide and install base plates, hex nuts, and connection bolts -Align frame and torque bolts Likely Schedule Activity for Steel Framing: -Provide and install structural steel framing
RSMeans Unit Price Data
Presented as "National Avg. Cost" - Unit pricing has three components • Materials • Labor (union rates, varies by trade) • Equipment (as applicable) - Unit pricing presented as "bare" (direct costs) and "total" (direct + O&P) • GC self‐performed work would typically use "bare" cost data (with normal GC "close‐out" components) • "Total" includes installer's labor burden, home office overhead, and profit; used for subcontractor estimates • RSMeans uses 10% for O&P on installer's materials, labor, and equipment; labor burden is additionally included • RSMeans labor burden varies by trade (as a National Avg. value for the trade); see inside of back cover
Duration - Role of Productivity
Productivity is a measure of production output per unit of time, relative to a resource input (i.e. labor and/or equipment); such as how much material is installed or moved per hour or day Example: Labor - 2‐person carpenter crew can install 2,000 SF/day of ½" drywall - Two, 2‐person crews install 4,000 SF/day Example: Equipment - Hydraulic excavator equipped with 1/2 CY bucket moves 200 CY/day - 2 ½ CY bucket moves 850 CY/day
Unit Price Method variables
Q = total quantity of item C = unit cost of item,(material, labor, equipment)
Duration Estimating - A Process
Review the activity's scope of work (SOW) • Identify the characteristics of the planned activity • Select means and methods, and assign level of resources (check resource calendars for availability) • Consider site‐specific issues that may impact productivity • Consider inter‐dependencies of tasks that make up the activity, or to other interfacing activities • Consider which estimation technique is most applicable Document your work • Assumptions involved in estimating the value (labor skill, weather, etc.) • Constraints that influence the value (other activity influences) • Level of accuracy (or reliability) of value • Indispensable when updating the duration estimate
Schedule General Comments
Routinely update the schedule: • Activity durations are estimates, update with actual performance to improve accuracy • Accounts for work completed (supports payment requests) • Accounts for change order modifications, and concealed/unknown conditions, and other delays • Contract often stipulates the required frequency of updates (e.g. monthly) Incorporate "milestones" into the schedule: • Represent key events in the project timeline (e.g. "topping out", "dry in", inspections, etc.) • They consume no time or resources, and not assignable to a project member • Included to facilitate evaluation of interim progress Distribute the schedule: • It is an effective communication and coordination tool • Include owner, designers, subs, fabricators, suppliers, etc.
Logic (Planning) + Duration =
Schedule
"Calendar Dates" for Scheduled Activities
Scheduling involved: • Adding duration time (i.e. planning units as number of days) to activities in the logic diagram • Network computations established activity start and finish days, as sequential numbering count • Need to relate "counting days" to actual "calendar dates" Calendar dates: • Define the project's "working days" - M‐F or M‐Sa - Answers "when is work expected to occur" • Define which calendar will be used - Federal, state, owner‐specific (e.g., VT)? - Project specified?
Duration Estimating Example Steps
Step 1 - Calculate the units of work involved (compute any wall and ceiling surface areas, etc) Step 2 ‐ Locate activity productivity data in RSMeans reference:
"Total" Float
The amount of time that an activity can be delayed without delaying completion of the project (i.e. impacting critical path) Total Float = LFActivity - EFActivity (or LSActivity - ESActivity)
RSMeans unit pricing data does...
not provide the most current material and labor pricing data.
Project scheduling techniques such as CPM are...
not unique to the construction industry.
The goal of the quantity takeoff process is to quantify every item of the project.
True
RSMeans' "Quantity Takeoff" (QTO) Tips
Use preprinted forms for organization and guidance • Use front side of form/paper only (the back can be overlooked) • Use consistent format for dimension entry (length x width x height) • Use stated dimensions where given, and add up multiple stated values for a single entry • Measure all other dimensions carefully (check drawing scale) • Convert foot‐inch dimensions to decimal feet for recording (e.g., 7'‐5 ¾" → 7.48') • Do not "round off" computed quantities until the final summary • Develop a pattern for performing the estimate, for example: - Start QTO at lowest floor and move upward to next floor - Proceed from main section of building, then to the wings - Proceed north to south, or vice versa, or CW or CCW - Perform QTO of floor plans first, then elevation views next, followed by details • Utilize design symmetry or repetition (floors, wings, room layouts) • Do not convert units until the final total is obtained; for instance with concrete, keep all measurements in CF units, then summarize and convert to cubic yards • May need to add items to properly account for a complete project (i.e. false work, staging, etc.)
Generalized Planning Process
WBS and CPM
Detailed estimates are made with very little information known about the project.
a lot of information known about the project.
Networks are...
continous
Scheduling relationships among work activities (and trades) begins to form...
during the quantity takeoff process
The pricing of material unit costs is than the pricing of labor unit costs...
easier than the pricing of labor unit costs.
In the typical purchasing sequence...
the submittal is made by the vendor, approved by the general contractor, designer, and owner, with final fabrication by the vendor to follow.
Duration - The Construction Context
• "Duration is the estimated number of work periods needed to complete an individual activity with estimated resources" (Project Management Institute) • Duration period is often referred to as a "planning unit" - Typically expressed in days - Hour, week, and month units also used (as applicable) - Unit must be consistent throughout schedule • Duration is a function of the resources assigned to the activity (type and quantity) • Two approaches to duration estimating - "Top‐down" - allocate duration planning units to an activity, and assign sufficient resources to complete on time - "Bottom‐up" - plan tasks and roll‐up task times to establish the activity's duration planning units Why estimate duration? • Scheduling - To know when activities will (and need to) occur - To estimate the construction project length, and completion date - To check that means and methods and assigned resources are sufficient for allotted time • Cost Estimating - Resources assigned to meet an activity duration establishes costs
WBS Levels
• A WBS illustrates the relationship between an activity (i.e. work task) and the overall scope of work (i.e. project) • Level 0 is the deliverable • Level 1 represents major components (i.e. work packages), which collectively must capture 100% of deliverable scope (e.g. the complete retaining wall) • Level 2 (and lower) are unique activities that create the associated major component (Level 1) • Decompose the work until each activity is managed by a single entity, and/or further decomposition adds no value
Scheduling Terminology
• Activity Number - only identifies an activity, not its sequence • Duration - estimated time (usually days) to complete the activity • Early start (ES) - earliest day number activity can start, based on network logic (i.e., predecessor "links") • Early Finish (EF) - earliest day number activity can finish (EF = ES + duration) • Late Finish (LF) - latest day number activity can finish without delaying project completion, based on network logic (i.e., successor "links") • Late Start (LS) - latest day number activity can start without delaying project completion; based on LF and activity's duration (LS = LF - duration)
Estimating Duration - Adjustments
• Add time between activities of different trades (time is lost in transition) • Add time based on experience with a specific subcontractor (past performance informs) • Add time for weather; random (day to day) or systematic (seasonal)? • Space congestion (will it be an issue?) • Activity location accessibility (ground level, 5th level, long distances?) • Activity window restrictions (day, night, or short shifts?) • Learning curve (are there repetitive elements allowing it to play out?) • Overtime (can lower unit productivity) • Design changes and/or rework (after start of activity)
Estimating Duration - Unaccounted Factors
• Bad weather (large snow event, hurricane, prolonged wet weather) • Change orders (unforeseeable) • Unanticipated site conditions, whether subsurface or hidden within an existing structure (whether unforeseeable or unforeseen) • Equipment breakdowns (unplanned) • Late material deliveries (unforeseeable) • Problems with submittal approvals (incomplete documents or slow turnaround by designer/owner) • Accidents, fires, labor strikes • "Historical artifacts"
Unit Price Cost Estimating Concept
• Calculation of the approximate materials and labor to build a project • Skills Required: - Ability to read project documents (drawings and specifications), and scale dimensions on drawings - Math proficiency - Mentally visualize the project work required - Knowledge of construction methods and materials - Ability to assemble project materials and activities into "work packages"
Schedule Activity is often a "Bundle" of Cost Line Items
• Cost estimate line items quantify pricing (itemization necessary) • Schedule activity is for planning, monitoring, and controlling the work • A schedule activity is the work managed by a single "owner," and where further decomposition adds no scheduling value Example - door hinges (Item 3), locksets (Item 4), panic devices (Item 5), and thresholds (Item 6) are too granular for scheduling needs • Schedule activity (one item) is the "bundle" of cost Items 1 through 6
What is a Work Activity (Task)?
• Definable part of the overall project (a necessary work task) • Consumes project time and resources • Measurable (an itemized unit of work and its location) • Assignable to a single project member (no overlaps) • One of three types: - Production (physical construction) - Procurement (materials, equipment, subcontractor coordination) - Administrative (inspections, permitting, project meetings, etc.)
Duration Estimating - Parametric Technique
• Duration data is characterized on a unit measure basis - Days/SF of asphalt pavement - Hours/SF carpet installation - Hours/CY concrete placement, etc. • Expected Duration = # of units in activity x time to produce 1 unit • Based on historical data and statistics • RSMeans dataset is an example of a parametric technique • Loose resolution of project‐specific factors in the data ("averaged") • Reduces an estimator's bias
Parametric Method
• Duration data is characterized on a unit measure basis: - Days/SF of asphalt pavement - Hours/SF carpet installation - Hours/CY concrete placement, etc. • 𝐸𝑥𝑝𝑒𝑐𝑡𝑒𝑑 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛 ൌ # 𝑜𝑓 𝑢𝑛𝑖𝑡𝑠 𝑖𝑛 𝑎𝑐𝑡𝑖𝑣𝑖𝑡𝑦 ൈ 𝑡𝑖𝑚𝑒 𝑡𝑜 𝑝𝑟𝑜𝑑𝑢𝑐𝑒 1 𝑢𝑛𝑖𝑡 • Based on historical data and statistics (needs strong correlation to be valid) • RSMeans dataset is an example of a parametric technique • Lacks resolution of project‐specific factors in the data ("averaged") • "Top‐down" duration estimating practice • Reduces an estimator's bias
Duration - "Progressive Elaboration"
• Duration is always an estimate...UNTIL COMPLETED • Updated at regular intervals during construction phase: - Actual performance "informs" updated duration estimate - Changes in predecessor and successor activities "informs" updated duration estimate - Updated material delivery schedules "informs" updated duration estimate • Activities on the schedule's critical path directly effect the project timeline, and justify a high level of monitoring and accuracy
Duration Estimating - "Bottom‐Up"
• Duration is estimated on a granular level, for tasks that make up an activity • Planning units for the tasks are then "rolled‐up" for the activity duration • Activity durations are then "rolled‐up" for the work package duration • Can be accurate, because those responsible for the work are estimating the duration (more knowledge than "top‐down" approach) • Sum of activity durations may not accurately represent needed planning units for work package, because it may ignore inter‐dependencies • Can be prone to biases or "interests" of the work package "owner" who is developing the duration estimate • "Disjointed" approach since durations created by many different work package "owners" • Requires more effort than "top‐down" approach - Work package "owner" estimates resources (labor, materials, equipment, space), planning units (durations), and costs of activities under their work package
Expert Judgement Method
• Estimator (or group of estimators) determine the "expected" duration based on experience and expertise • Typically no computations • Accuracy can vary broadly, being a function of: - Characteristics of the work - Estimator's experience • "Top‐down" duration estimating practice • Be careful choosing experts (internal and external), or using their estimates, their biases may influence their estimate (e.g. experience only with a single method)
Analogous Method
• Estimator makes an analogy to the same, or similar, activity that has been performed before • Based on historical data (and estimator's recollection) • Typically no computations, except for adjustments: - Scope/size - scale up or down by the appropriate parameter (e.g. SF of carpet, LF of driveway, etc.), include contingency for associated, unquantified factors - Specialty products/services (that the last project did not have) - add for specialty scope duration (e.g. lead time, installation, etc.) - Slightly different end‐product (quality) - determine difference in workmanship required and impact on duration • "Top‐down" duration estimating practice • Only as reliable as the past activity's duration!
Why is a CPM only a Projected Plan?
• Flawed logic • Imperfect duration estimates • Missing tasks • Personnel shortages • Material delays • Weather
"Network Logic Diagram"
• Flow chart of all work activities needed to complete a project (from WBS) • Depicts work activity inter‐dependencies and sequencing (i.e., constructor's "job plan") • Preference and/or experience can shape the sequencing order • Not drawn to any scale; activity order is the objective
Logic Relationships ("Inter‐dependencies")
• Modelling of inter‐dependencies between activities (that will occur in the field) • Specifies when an activity starts or finishes relative to another activity • Enables "overlap" of activities (if desired) • Recognizes that activities are not perfectly sequential, but may be concurrent (i.e. parallel)
"Critical Path"
• Outcome of a network schedule (logic diagram with activity durations included) • Definition: "The path of activities which requires the longest total time for project accomplishment" • A delay in any activity on the critical path causes a delay in completion of the overall project • The network's "critical path" determines the minimum project schedule, which needs to be compared to the contract completion date (and adjustments made to the work plan as necessary) • The critical path may change from time to time throughout a project, as activities are completed ahead of or behind schedule
Network Concepts
• Parallel (or concurrent) - two or more independent activities that can be performed at the same time, if desired (ex. A, D, and F) • Burst activity - activity that has two or more activities that follow it (ex. A) • Merge activity - activity that has two or more activities that precede it (ex. E and C) • Driving Relationship - an activity whose finish (or start) controls the start (or finish) of a dependent activity
Estimating Duration - Considerations
• People usually work only 45 to 50 minutes/hr; labor productivity data typically takes this into account • Estimate durations one activity at a time: - Initially assume required resources are available - Assume normal level of manpower and equipment - Assume normal work day (may or may not be 8 hours per day) • Don't try to "fit" available time (this is only wishing) • If duration is unacceptable, change approach (means and methods) or increase resources (i.e. multiple crews)
Work Breakdown Structure (WBS)
• Purpose is to decompose the project into necessary work tasks • Must identify all work tasks, termed "activities" • No overlap or omission of activities • Accounting exercise only; no durations or inter‐dependencies at this stage • First planning step of a project • Break the project down (i.e. decompose) into all of it's necessary activities • Group the activities into related "work packages" (i.e., specific parts or deliverables), each having a schedule and budget that can be coordinated and controlled • Create a "tree" diagram to provide a visual, hierarchical organization of the total project scope
Typical Planning Actions
• Review the bid documents (drawings, written specifications, supplemental information, etc.) • List the project objectives and scope of work (SOW) • Visit the project site (crucial) • Identify potential problems and/or conflicts • Outline a general sequence of major activities • Decide on construction techniques and equipment (i.e., means and methods) • Draft a rough "logic diagram" of activities • Identify any "long‐lead" items and/or "owner‐supplied" materials and equipment • "Inform" your planning decisions by conducting meetings with - Internal estimator, project manager, and scheduler - Key superintendents and foremen - Owner, suppliers, and utility companies
Scheduling and Estimating are Linked
• Scheduling develops naturally and simultaneously with estimating (QTOs) • QTOs identify - What components and activities are required in a project - Sequencing relationships between the components and activities (i.e. order dependencies) • How the components and activities will be accomplished (i.e. means and methods selected) affects both cost and schedule
Network Conventions
• Single starting point and finishing point • Single work activity at a node (if not, decompose) • Continuous (i.e. a predecessor(s) and successor(s) to each activity, except the first and last) • No activity can start until all predecessor "links" have been accomplished
Network Schedule
• Thorough planning is key to project success • Planning is a component of scheduling - Developing the "logic" diagram is a planning process - Addition of activity durations makes it a scheduling process