1. CE 366 PROJECT MANAGEMENT AND ECONOMICS Robert G. Batson, Ph.D., P.E. Professor of Construction Engineering The University of Alabama Rbatson@eng.ua.edu

2. Chapter 12: Scheduling Applications 2

3. Role of the Schedule Whereas the owner and his design representatives focus on the end product, through drawings and technical specifications... The contractor focuses on process, and defines the object of the contract through the cost estimate and bid documents, and the baseline schedule The schedule is a work process model that communicates when materials, equipment, labor and other resources will be applied in order to arrive at the end product –evolves as the project proceeds –serves as a basis for the application of resources and the periodic accumulation of costs 12.1

4. Operational Schedules A.Baseline (as-planned) Schedule –communicates original intent of contractors –owner and contractor should review and validate –a basis for evaluating performance and proposed changes B.Updated Schedule (an as-built schedule in progress) –monthly updates with actual project logic and times –logic changes and revised time inputs with revised CPM output C.Short-Term (4-6 weeks) Look-Ahead Schedule D.As-built Schedule (documents the project history) –documents actual start-finish dates for each activity and date each milestone was achieved –documents delays, change orders, extra work, weather effects, etc. 12.2

5. Schedule Presentation Formats A.Precedence networks (see Figure 5.6) –used to plan and re-plan project activities and logic –nodes capture information in a concise manner, with opportunity to link to text or to costs –sets stage for use of CPM B.Gantt Charts –easy to read, widely understood –the basis for resource histograms and management C.Time-Scaled Logic Diagram (a blend of A & B) –shows time-phased interplay between activities D.Line-of-Balance Chart (Figure 5.16) –used for linear builds such as roads, railways, pipelines –compact, but more complex to read than Gantt chart 12.3

6. Schedule Analysis to Determine Project Delays Delays occur when activities start later than LS or finish later than LF, or when milestones (arrival of materials or equipment on-site) experience slippage Delays are reflected in updated schedules by adding more time to activities, recording actual LS and LF times, and/or through the addition of new activities If contractor is responsible, time must be made up at its expense If owner is responsible, the contractor must notify owner of cost and schedule impact, and request a contract change order By inserting the delay into the CPM schedule update to the point of delay, and rerunning CPM, changes in critical path duration are estimated 12.4

7. Change Order Process Flowchart (Figure 12.2) If owner agrees to contact change order, and the adjusted cost and schedule, the delay issue is settled If owner rejects responsibility for the delay, then the contractor must either let the issue drop or give notice he reserves right to file a formal claim Contractor must decide whether to depend on success of the claim, or to accelerate the job to stay on schedule It is better if the effects of a change are identified, quantified, and resolved at the time of the delay, by the people (on both sides) currently involved with the project 12.5

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9. Using the CPM Schedule to Support Claims Assume no schedule impact was developed at the time of the delay –entire scope of work changed –repercussions not apparent at time, so change order as approved was inadequate to cover cost/schedule impacts Once the project is complete, two categories of analytical approaches are used in conjunction with CPM: 1.Impacted Baseline Schedule: add delays to the baseline schedule to illustrate their effect and quantify them (using CPM) 2.But-for or Collapsed As-Built Schedule: using a copy of the as-built schedule, the delays are analyzed one-by- one working backward from the latest; each delay is “undone” by removing increased durations and additional activities due to that delay; CPM is rerun with each adjustment to show the cumulative effect 12.6

10. Legal Aspects of Project Schedules The project schedule, baseline and each iteration, is a legal document Almost all construction contracts have a specified completion date –Owner determines this date, and often has multiple contracts and logistical plans tied to the completion date –Early completion also affects owner financially, and may be a reason to insert early completion clauses in contract Contractor has a legal “right to finish early”, but should consider the six points on p. 298-299 before proceeding Delays must be still be documented (under an early- completion schedule), in case a claim is to be filed later 12.7

11. Legal Aspects of Project Schedules (Continued, I) Contract clauses require the owner’s review and approval of a project schedule –Owners frequently specify project milestones –Such clauses do not limit the contractor’s choice of construction means and methods Owner’s approval of schedule covers three elements: 1.Contractor’s schedule meets all requirement as set forth in the contract documents. 2.Contractor’s schedule provides owner with sufficient detail to develop other project-related schedules and monitor progress. 3.Contractor’s schedule must provide the owners with sufficient detail to analyze the effects of a proposed change (without involving the contractor directly) 12.8

12. Legal Aspects of Project Schedules (Continued, II) Contractor should provide owner with resource-loaded schedule –Demonstrates contractor knows which resource’s and what quantities are needed, by each activity –Indicates how resources will actually be scheduled (see quote p. 300 regarding this) Construction schedules, baseline and each interaction, convey to the owner the contractor intentions for delivering the final product through contracted scope of work –Schedules must be communicated to the owner and/or his representative is a format they can use –This assures the contractor’s interests are considered in the owner’s overall plans –Failure to provide schedules limits ability to recover costs of changes due to the owner 12.9

13. Handling Weather Effects Weather, in fact any “normal occurrence” or “commonly anticipated condition,” must be described and it’s anticipated effect interpreted to the owner Definition must be based on research (such as Figure 12.3) and must fit the location and conditions of the project Two ways to handle weather impacts on schedule 1.Build contingency into time estimates for potentially affected activities, or at the end of the project 2.Use weather calendars to distribute delay weather affects randomly over the project, to those activities sensitive to rainfall in ranges [0.1, 0.2), [0.2, 0.5), [0.5,  ). 2.10

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15. Handling Weather Effect (Continued) The weather calendar method: –distributes the effect of weather delay realistically over the entirety of the schedule (Figure 12.4) –provides a truer status of the project at each update As the schedule is updated it is important to record actual rain days (extend activity times accordingly) and remove predicted rain days Do not postpone scheduling in the actual weather effects until the project is completed If worse-than-expected weather causes the project to fall behind in any one month, a contract extension should immediately be requested (a basis for a later claim, if not granted) 15.11

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17. Handling other Unknowns (Risks) Many construction activities have been performed before on other company contracts, and the time and production rate information is reliable Other activities may be new to the contractor and require additional effort to quantity a “safe” activity duration and resource commitment, for example: –different materials from experience base –inexperienced work crew –subcontractor without a “track record” working with you –new equipment and/or method at the workface During project planning, frank discussions about uncertainties should occur; research should follow, and plans adjusted accordingly Contingency at end helps where estimates were too optimistic, uncertainties materialize, or to handle unknowns 12.12