CON-210 · Lesson 10 of 12 · 32 min
Scheduling specifications, contract requirements and schedule quality
On most projects the construction schedule is not just a management tool; it is a contract document, or at least a contract deliverable. The contract says when the schedule must be submitted, what it must contain, how often it must be updated, who reviews it, and what happens when it shows delay. On larger projects a detailed scheduling specification can run to dozens of pages and set rules for activity durations, logic, constraints, float, cost loading, narratives and software formats. Courts, adjudicators and arbitrators later rely on the schedule submittals to decide who caused delay and who pays. This lesson explains the contract framework for schedules, the content of typical scheduling specifications, the review of baseline schedules, the question of float ownership, and the quality checks reviewers use.
The contract framework
In the United States, many private building contracts use the American Institute of Architects (AIA) documents. Section 3.10.1 of AIA A201-2017, General Conditions of the Contract for Construction, requires the contractor, promptly after being awarded the contract, to submit for the owner's and architect's information a construction schedule that does not exceed time limits under the contract documents, is revised at appropriate intervals as required by the conditions of the work, and provides for the orderly progression of the work to completion. Section 3.10.3 requires the contractor to perform the work in general accordance with the most recent schedules submitted. Federal construction contracts include FAR clause 52.236-15, Schedules for Construction Contracts, which requires a practicable schedule and allows the contracting officer to withhold approval of progress payments if the contractor fails to submit one, and federal agencies and state departments of transportation often add detailed CPM specifications.
Note what the general conditions do and do not say. They require a schedule, set its basic purpose and require updates. They usually do not specify the method, the level of detail, the treatment of float or the format. Those details belong in the specifications, typically in MasterFormat section 01 32 16 Construction Progress Schedule or a similarly named section.
What a scheduling specification typically requires
Scheduling specifications vary widely, from a single page on a small project to forty pages on a major public works contract. Common requirements include:
- Method and software: a critical path schedule in the precedence diagramming method, often in a named software format, such as Primavera P6 files, with native files submitted, not just printouts.
- Timing: a preliminary schedule within a short period after award, often 10 to 30 days, and a detailed baseline within 30 to 60 days.
- Content: all work, including submittals, procurement, fabrication, delivery, inspections, owner activities, commissioning and closeout.
- Activity rules: maximum durations for construction activities, often 15 or 20 working days; descriptive names; codes for area, trade and responsibility.
- Logic rules: every activity with a predecessor and successor; limits or bans on leads, lags, start-to-finish links and hard constraints.
- Calendars: working days, holidays and weather days, often with a table of anticipated weather days per month.
- Cost or resource loading: activity costs that sum to the contract price and tie to the schedule of values, used to check progress payments.
- Updates: monthly updates with actual dates, remaining durations and percent complete, submitted before or with each payment application.
- Narratives: a written report with each submittal explaining the critical path, changes in logic or durations, delays, and corrective action.
- Time impact analyses: a fragnet analysis to support any request for a time extension (Lesson 11).
- Float: a statement of who owns float, and a ban on sequestering float, for example by inflating durations or using preferential logic to consume it.
The baseline submittal and review
The baseline schedule, once accepted, is the yardstick against which every later update is measured. Reviewing it carefully is one of the most valuable things an owner's team can do. A thorough review looks at the following.
- Compliance: does the schedule meet the specification's format, content, activity, logic and calendar rules?
- Completeness: are all the scope, milestones, owner activities and interfaces with other contracts included?
- Logic: does the sequence make construction sense? Are there open ends, excessive constraints or suspicious lags?
- Durations: are they reasonable for the quantities and resources, and consistent with the cost loading?
- Critical path: is it continuous from the start to completion, and does it pass through the work an experienced builder would expect?
- Float: is float distributed plausibly, or is it hidden by preferential logic, inflated durations or early finish dates?
Owners usually accept, or accept with comments, rather than approve the schedule, so as not to take responsibility for the contractor's means and methods. Accepting a schedule that shows the work finishing early, however, can have consequences: some contracts and decisions have treated the time between an accepted early finish and the contract date as available to the contractor, a question tied to float ownership.
Worked problem
Reviewing a baseline against specification limits
A scheduling specification limits construction activities to 20 working days, requires every activity except the first and last to have a predecessor and successor, and allows hard constraints on no more than 2 % of activities. The contractor's baseline has 420 activities. The reviewer finds 31 construction activities longer than 20 days, 12 activities with no successor, and 14 hard constraints. Which requirements are not met?
Show solution
- Durations: 31 activities exceed the 20-day limit, so the duration rule is not met unless they are justified (for example, procurement or curing activities that the specification exempts).
- Logic: 12 open ends violate the predecessor and successor rule.
- Constraints: 14 ÷ 420 = 3.3 %, which exceeds the 2 % limit.
- The reviewer returns the schedule with comments listing each non-compliance and asking for corrections before acceptance.
Answer: All three requirements are breached: long activities, 12 open ends and 3.3 % hard constraints.
Schedule quality checks
Owners, lenders and auditors use standard checks to assess schedule quality. In the United States, the Defense Contract Management Agency's 14-point assessment, developed for defense programs, has become a widely used benchmark across industries, including construction. Its thresholds are guidelines rather than rules, but they give reviewers a consistent starting point.
| Check | What it measures | Typical threshold |
|---|---|---|
| Missing logic | Incomplete activities without a predecessor or successor | ≤ 5 % |
| Leads | Relationships with negative lag | 0 % |
| Lags | Relationships with positive lag | ≤ 5 % |
| Relationship types | Share of finish-to-start links | ≥ 90 % |
| Hard constraints | Activities with mandatory dates | ≤ 5 % |
| High float | Incomplete activities with more than 44 working days of float | ≤ 5 % |
| Negative float | Activities with float below zero | 0 %, or explained |
| High duration | Incomplete activities longer than 44 working days | ≤ 5 % |
| Invalid dates | Forecast dates before the data date, or actual dates after it | 0 |
| Resources | Activities with durations but no resources or cost, where loading is required | Reported |
| Missed tasks | Activities that should have finished by now but did not | ≤ 5 % |
| Critical path test | Whether delaying a critical activity delays the finish | Pass |
| Critical path length index (CPLI) | Efficiency needed to finish on time | ≥ 0.95 |
| Baseline execution index (BEI) | Tasks finished compared with tasks planned to finish | ≥ 0.95 |
Many US public owners, including federal agencies and state departments of transportation, write the DCMA-style checks directly into their specifications, and the US Government Accountability Office's Schedule Assessment Guide sets out best practices for federal program schedules.
Worked problem
Calculating two DCMA metrics
At an update, 180 activities in a schedule were planned to finish by the data date; 153 actually finished. The remaining duration on the critical path is 90 working days, and the project has 6 days of total float on the critical path relative to the contract date. Calculate the baseline execution index (BEI) and the critical path length index (CPLI).
Show solution
- BEI = tasks completed ÷ tasks planned to be complete = 153 ÷ 180 = 0.85.
- CPLI = (critical path length + total float) ÷ critical path length = (90 + 6) ÷ 90 = 1.07.
- BEI below 0.95 shows the team is completing fewer tasks than planned, a warning sign even though the critical path still has positive float.
- CPLI above 1.0 shows there is some margin on the critical path; below 1.0 would show the team must work more efficiently than planned to finish on time.
Answer: BEI 0.85 (below the 0.95 guideline) and CPLI 1.07 (healthy). The project is slipping on non-critical work and needs attention.
Float ownership
Float is valuable. A contractor that uses float to absorb its own problems, such as a late crew, has less protection if the owner later causes a delay on the same path. An owner that consumes float through slow approvals or late changes may reduce the contractor's flexibility without extending the contract time. Who owns float therefore matters a great deal in delay disputes.
- Project float, or shared float: float belongs to the project and is available to whichever party needs it first. A delay that consumes float does not extend the contract time; only delay to the completion date does. This is the most common position in modern specifications.
- Contractor float: float belongs to the contractor, who scheduled the work, so owner delays that consume it may give rise to compensation even if the completion date is not affected.
- Owner float: rare, but some contracts reserve float to the owner.
- Allocated float: some approaches divide float between the parties or allocate it activity by activity.
The AIA A201 general conditions do not address float ownership, so it is set in specifications. Many federal and state specifications say that float is not for the exclusive use or benefit of either party and is a shared resource of the project. Boards of contract appeals and courts have generally applied the shared-float approach where the contract says nothing else, and AACE International's recommended practices are widely cited in disputes.
Worked problem
Who bears a delay on shared float?
A non-critical path has 10 days of float. The contractor's crew is late, using 4 days. Later, the owner's consultant takes 9 days longer than allowed to review a submittal on the same path. The contract says float belongs to the project. How much time extension, if any, is the contractor entitled to?
Show solution
- After the contractor's 4-day delay, the path has 10 − 4 = 6 days of float left.
- The owner's 9-day delay consumes the 6 days and delays completion by 9 − 6 = 3 days.
- Under shared float, the contractor is entitled to a 3-day extension for the owner-caused delay to completion, not 9 days.
- If the contractor had not used 4 days first, the owner's delay would have been absorbed by float and no extension would be due: the first to use float gets the benefit.
Answer: 3 days. Under shared float, whoever uses float first benefits; the remaining delay to completion is what counts.
Sequestering float and other abuses
Because float has value, both parties sometimes try to control it unfairly. Contractors may inflate durations, add preferential logic or use constraints so that few activities show float, leaving almost every owner delay on the critical path. Owners may insist on unrealistically short durations so that the contractor has no float, or schedule their own activities to use float. Specifications counter these practices by requiring durations to be supported by resources and quantities, by prohibiting float suppression techniques, and by giving the owner's reviewer the right to reject unrealistic logic.
Forensic schedule analysis
When delays become disputes, experts reconstruct what happened using the schedule submittals and project records. AACE International's Recommended Practice 29R-03, Forensic Schedule Analysis, classifies the methods in use, such as as-planned versus as-built comparisons, windows analysis using contemporaneous updates, impacted as-planned and collapsed as-built analyses, and time impact analyses. The details belong in the claims course (CON-420), but the lesson for schedulers is simple: regular, accurate, well-documented updates are the best evidence any party can have. A project with no reliable updates forces experts to rebuild history from diaries and photographs, which is expensive and uncertain for everyone.
Worked problem
Liquidated damages and an extension
A contract has a completion date of working day 300 and liquidated damages of $3,500 per calendar day. The project finishes on working day 318, which is 25 calendar days late. The contractor proves that owner changes caused 10 working days of delay to completion, equal to 14 calendar days, and receives an extension. How much in liquidated damages is owed?
Show solution
- Calendar days late without extension: 25.
- Extension granted: 14 calendar days.
- Days of contractor-caused delay: 25 − 14 = 11 calendar days.
- Liquidated damages: 11 × $3,500 = $38,500.
Answer: $38,500 for 11 calendar days, after the 14-day extension.
Common mistakes
MistakeTreating the schedule as an internal document only.
InsteadRead the general conditions and Division 01 for schedule requirements, deadlines and formats.
MistakeSubmitting a baseline full of hard constraints and open ends.
InsteadCheck the schedule against the specification and quality metrics before submitting.
MistakeApproving the contractor's schedule as if responsible for its methods.
InsteadAccept or accept with comments, and review logic and durations critically.
MistakeIgnoring float ownership until a dispute arises.
InsteadRead the float clause and document who uses float and why.
MistakeLetting updates lapse.
InsteadUpdate regularly; contemporaneous updates are the best evidence in a dispute.
Summary and key terms
- AIA A201-2017 §3.10 requires a schedule promptly after award, revised at appropriate intervals; FAR 52.236-15 applies on federal work.
- Detailed scheduling requirements are set in Division 01, often section 01 32 16.
- Specifications govern method, timing, content, activity and logic rules, calendars, cost loading, updates and narratives.
- Baseline reviews check compliance, completeness, logic, durations, critical path and float.
- The DCMA 14-point assessment provides widely used schedule quality metrics.
- Float ownership, usually shared project float, affects time extensions.
- Forensic schedule analysis relies on regular, accurate updates.
- Scheduling specification
- The contract section that sets requirements for the construction schedule.
- Baseline submittal
- The detailed schedule submitted for acceptance as the basis for measuring progress.
- Schedule narrative
- A written report explaining the schedule, critical path, changes and delays.
- DCMA 14-point assessment
- A set of schedule quality checks developed by the US Defense Contract Management Agency.
- Baseline execution index
- Tasks completed divided by tasks planned to be complete by the data date.
- Critical path length index
- A measure of the efficiency needed to finish on time, using critical path length and float.
- Float ownership
- The contractual rule about which party may use schedule float.
- Shared float
- Float available to whichever party needs it first.
- Float sequestering
- Practices that hide or consume float unfairly, such as inflated durations.
- Forensic schedule analysis
- Analysis of schedules after the fact to determine the causes and effects of delay.
Practice problems
Work each problem on paper first, then reveal the answer to check.
Under AIA A201-2017, when must the construction schedule be submitted?
Show answer
Promptly after the contract is awarded.
In which MasterFormat section are scheduling requirements commonly found?
Show answer
01 32 16 Construction Progress Schedule.
Name four requirements typical of a scheduling specification.
Show answer
Any four of: method and software, timing, content, activity duration limits, logic rules, calendars, cost loading, updates, narratives, float rules.
A schedule has 500 activities and 20 hard constraints. What percentage is that?
Show answer
4 %.
BEI: 90 tasks planned, 81 finished. What is the BEI?
Show answer
0.90.
CPLI: critical path 120 days, float 0. What is the CPLI?
Show answer
1.00.
What does shared float mean?
Show answer
Float belongs to the project and is available to whichever party needs it first.
A path has 5 days of float; an owner delay of 8 days occurs. Extension under shared float?
Show answer
3 days.
Why do owners usually accept rather than approve schedules?
Show answer
To avoid taking responsibility for the contractor's means, methods and sequence.
What is the best evidence in a delay dispute?
Show answer
Regular, accurate, contemporaneous schedule updates with narratives and records.
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