PURPOSE
The type of construction schedule utilized depends on the specific project requirements. The purpose of this section is to provide guidelines for selecting the appropriate construction schedule specification to fit the project prior to bid. The following goals have been identified for project scheduling:
To provide an overall status report.
To coordinate a project’s timeframe with other contracts and the Client’s needs.
To permit close monitoring of the Contractor’s progress.
To provide a basis for monitoring the potential schedule impact of change orders and claims
To provide a basis for remedial action as necessary.
To provide a basis for payment when the Bureau of Contract Administration agrees to use the cost loaded schedule.
REFERENCES
Standard Specifications for Public Works Construction (Green Book) – Section 6 – Prosecution, Progress and Acceptance of the Work
RESPONSIBILITIES
Project Manager (PM): The PM is responsible for selecting the appropriate construction schedule specification and establishing the overall contract duration for the project. The PM should consult with the Construction Manager when making the selection. On small projects, the PM may defer to the Project Award and Control Division to determine the contract duration. The PM also must determine whether the schedule duration for the project will be calendar-day or working-day. Calendar-day schedules are appropriate for larger, more complex projects. For smaller, simpler Green Book projects (where submittal, approval and procurement activities are less likely to be critical) a working-day schedule makes more sense. Historically, the Construction Manager has been responsible for schedule control of calendar-day projects. On smaller Green Book projects, the PM has the discretion to defer the schedule review and tracking responsibility to the Lead Inspector.
Construction Manager (CM): The CM provides guidelines to the Contractor for the development of the construction schedule, reviews and accepts the project’s baseline schedule, reviews the monthly schedule update submittal for acceptance, and provides comments on the schedule submittals. The CM also reviews recovery schedules, delay claims, and Time Impact Analysis submitted by the Contractor and approves the inclusion of a time extension in change orders, when required.
Contractor: The Contractor is responsible for the development of the construction schedule, as required by the contract specifications. Whenever the Short, Medium or Long versions of the schedule specification are used, the Contractor is responsible for updating the schedule on a monthly basis to reflect the actual status of the project (progress, changes, etc.). Each week, the Contractor is also responsible for producing a Three-week Progress Schedule listing the activities completed and in progress for the previous week and the activities scheduled for the next two weeks. The activity designation (description and ID number) should be consistent with the project’s baseline construction schedule. When the Green Book version of the schedule is used, the Contractor shall revise and update the schedule as required by the Inspector. The Contractor is also responsible for the development of recovery schedules and Time Impact Analysis for change orders, as required by the Contract Specifications.
Lead Inspector (LI): On working-day projects (usually using the Green Book schedule version), the LI has responsibility for tracking the schedule progress. The PM may also defer the initial schedule review responsibility to the LI. The LI must communicate with the PM and CM regarding the Contractor’s performance and schedule delays. The PM needs to keep the project stakeholders informed regarding schedule progress and the CM needs to write any change orders to cover justified time extensions.
PROCEDURE
In this Procedure, the PM and the CM should be familiar with the four schedule versions utilized by the Bureau (1 Green Book and 3 from the Master Specifications, GR Section 01321). This Procedure also includes the CM's responsibilities in the Pre-construction Scheduling Conference.
Schedule Options
There are three different schedule specification versions in the Master Specifications (see Links / Attachments section) which are generally based on project size and complexity. Also, there is a Green Book version, which is typically used for small, non-complex projects. The three schedule versions in the Master Specifications are used for calendar-day projects, while the Green Book version is more suitable for working-day projects. The PM must select the schedule specification version described below that is the most appropriate for the project and edit that version to include project specific requirements. The following are brief summaries of the scheduling requirements for the Green Book and the three schedule specification versions in the Master Specifications:
Green Book Schedule Version: This version is used for straightforward sewer, storm drain or street projects with a construction value less than approximately $1,000,000. The schedule requirements are in Section 6 of the Green Book. This version is a bar graph or tabulation with no logic ties between the schedule activities.
Short Schedule Version: The Short Version is used for small, noncomplex projects with estimated project costs of less than $1 million, or larger projects that require few interfaces and minimal coordination with other projects. The Short Version schedule specification allows the Contractor to submit either a Critical Path Method (CPM) or a detailed bar chart schedule. This is the only Master Specification version that does not mandate a CPM schedule or the use of scheduling software.
Medium Schedule Version: The Medium Version is used for small, noncomplex projects with estimated project costs of $1 million to $5 million that require few interfaces and minimal coordination with other projects. The Medium Version schedule specification requires the Contractor to submit a detailed CPM schedule using specialized software, Primavera P6 (latest edition) or Microsoft Project (latest edition).
Long Schedule Version: The Long Version is used for projects with estimated project costs greater than $5 million, or smaller size projects with a high degree of complexity or interfaces with other projects. The Long Version schedule specification has several upgrade options that are used for large, complicated projects, which may require 2 to 3 months to arrive at an approved project schedule. This version requires the Contractor’s construction schedule to be a CPM schedule. The Contractor is to use Primavera P6 (latest edition) to develop the schedule. For the Short, Medium and Long versions described above, the cost to perform the work activity is to be noted for each activity of the schedule on a tabular listing. The sum of the costs assigned to all activities must be equal to the contract value.
Three-week Progress Schedule: The Short, Medium and Long schedule versions require the Contractor to also prepare Three-week Progress Schedules. Three-week Progress Schedules are bar graph schedules that show the work performed in the previous week and the work the Contractor is planning to do in the next two weeks. The Contractor should bring the updated Three-week Progress Schedule to the weekly construction meetings. Each bar on the schedule should include the related activity identification number from the project’s baseline schedule. The one-week history should be reviewed for accuracy at the weekly meeting so it can be used as a basis for the monthly update of the project schedule. The two-week look ahead can be used to give the Inspector advance notice of the work they need to inspect in the immediate future and enable the CM to establish priorities for processing Submittals, Requests for Information (RFI), Change Orders, Plan Clarifications, etc.
Schedule Presentation
The types of schedules utilized by the City are presented as either a bar chart or a time scaled logic diagram, which is better known as a Critical Path Method schedule. The two ways to present a schedule are described below:
Bar Charts: Most bar charts are kept rather simple in terms of content. A bar chart is generally comprised of horizontal bars with a time scale at the top. The bars represent the component of work items to be performed. Bars are drawn to graphically represent the span of time necessary to accomplish each work item. A bar chart is also known as a Gantt Chart. Bar chart schedules, by definition, do not indicate the successor or predecessor relationship of one bar to another.
Critical Path Method (CPM): A CPM time scaled logic diagram is a graphic presentation of the planned sequence of activities that show the interrelationships and interdependencies of the activities comprising a project. The Critical Path contains a series of related activities, which must be performed in sequence and whose cumulative duration is the longest. The CPM can be used for any of the three Master Specification scheduling versions described above.
Pre-construction Scheduling Conference
After the contract is awarded, the CM needs to hold a Pre-Construction Scheduling Conference with the Contractor’s PM and Construction Scheduler, within 7 calendar days after Notice of Award, to commence development of the required project schedule. At this meeting, the scheduling requirements, as they apply to the contract, will be reviewed with the Contractor. The CM should be prepared to review and discuss the methodology and requirements for the schedule, sequence of operations, cost, manpower and equipment loading methodology.
Establishing Construction Duration and Milestones
There are a few empirical rules the PM should keep in mind while customizing the project schedule requirements. Unless you have a simple, perfectly designed project, “Murphy’s Law” is going to take over at some point. For one reason or another, the project schedule will slip. Expect the project schedule to slip at least three months per year of planned construction time. If the PM has made commitments to the Owner, neighbors or have a subsequent contract that will be impacted by the current project, the best tool to gain some control over meeting the commitments is to establish the appropriate project milestones. There are four types of milestones typically used:
The Contractor can’t start work on a certain portion of the project until a specific date.
The Contractor can’t perform work on a certain portion of the project during a specific time window.
The Contractor must finish all or a portion of the Work within a specified period of time from Notice to Proceed.
The Contractor must finish work on a portion of the project within a specific calendar or duration window.
Liquidated damages must be assigned to the third and fourth types of milestones to make them enforceable. The project bid documents must build in the appropriate amount of float for all milestones during the design phase. Collaboration between the PM, CM, and the Project Award and Control Division is essential. For each type of milestone, the work must be defined and liquidated damages assigned for exceeding the completion dates. It is preferable to put this information in a separate “LIQUIDATED DAMAGES” subsection within Section 01112 – Description of Work of the General Requirements.
The construction schedule duration in the Uniform Project Reporting System (UPRS) should be longer than the contract duration. The construction schedule contingency should be at least three months. As a project becomes bigger or more complex, the schedule contingency may need to be increased.
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