Concurrent Delay in Construction: When Owner and Contractor Delays Collide on the Critical Path

Two delays, one completion date, and a very expensive disagreement

Consider a situation that is familiar on large construction projects. An $80 million public facility is approaching the most schedule-sensitive stage of its electrical work. Permanent power is needed before major systems can be energized, tested, commissioned, and turned over. The utility coordination and final owner-side design approvals have taken longer than expected, and permanent power is now forecast several weeks later than the date shown in the accepted project schedule. At the same time, the electrical subcontractor has its own problems. Rough-in production is behind plan, manpower has been inconsistent, and portions of the electrical rooms are not progressing at the rate shown in the last schedule update.

At the monthly progress meeting, the discussion quickly turns to responsibility. The contractor says the project cannot finish on time because permanent power has been delayed by matters outside its control. The owner responds that the electrical work would not have been ready anyway. Someone eventually uses the phrase that appears in so many project meetings and delay claims: “The delays are concurrent.”

That statement sounds straightforward. In practice, it may take weeks of schedule analysis and record review to determine whether it is correct.

Two delay events can occur during the same calendar period without having the same effect on project completion. One may be affecting the controlling sequence while the other sits on a path with available float. One may become critical only after the first problem has already delayed a milestone. The contractor may appear to be moving slowly because it is pacing work behind an earlier owner-caused delay. The critical path itself may change while both events are developing. By the time the dispute is formally examined, the schedule shown in a meeting six months earlier may tell only a small part of the story.

This is why concurrent delay is one of the more difficult areas of construction scheduling and delay analysis. It sits at the intersection of CPM mechanics, field conditions, contractual responsibility, causation, project records, and professional judgment. AACE International’s Recommended Practice 29R-03 devotes specific treatment to the identification and quantification of concurrent delays, including distinctions between literal and functional concurrency, cause and effect, analysis periods, critical paths, near-critical paths, and pacing. The subject remains very current. AACE’s July/August 2026 Cost Engineering journal includes a dedicated case-study article on mastering concurrent delays, reflecting how actively the industry continues to debate and refine these analyses.

For a project manager, superintendent, owner’s representative, scheduler, or claims professional, the practical lesson is more immediate. Concurrency should never be decided by looking at two bars on a schedule and observing that their dates overlap. The better question is whether each delay independently affected the controlling path to the relevant completion milestone during the same meaningful period. Answering that question requires us to understand what the critical path actually was when the events occurred.

The concurrency test most project teams get wrong

Two delays happening together are not necessarily concurrent

Suppose the permanent-power issue on our project began on May 4 and continued through June 26. During almost exactly the same period, electrical rough-in production fell behind the contractor’s planned quantities. On a simple timeline, the events overlap for most of May and June. If the analysis ends there, calling them concurrent seems reasonable. Yet a CPM schedule is concerned with relationships and effects, not merely overlapping dates. The question is what each event did to the completion forecast through the network of remaining work.

Assume the May schedule update shows that permanent power is on the longest path to substantial completion. Once permanent power is available, the project must proceed through energization, equipment startup, controls integration, functional testing, corrective work, and final commissioning. The delayed utility milestone is therefore directly influencing the forecast completion date. Electrical rough-in, however, still has 18 working days of total float. Its production is disappointing and deserves management attention, but the schedule indicates that the contractor can lose some time on that path without yet moving to substantial completion.

In that condition, the two events are happening at the same time, but they are not automatically producing concurrent critical delay. The owner-related permanent-power problem is affecting the controlling sequence. The contractor’s electrical production problem may be consuming float rather than extending project completion. If someone simply highlights both events on a calendar and calls the overlap “42 days of concurrent delay,” the analysis has skipped the most important CPM question.

The reverse situation can also occur. A contractor may be experiencing serious structural or MEP production problems that already control completion when an owner change is issued elsewhere on the project. The change may be significant, disruptive, and costly, yet still have enough float that it does not affect the contractual completion milestone during that particular period. Whether the change creates an entitlement to compensation for changed work is a separate issue. From a schedule-delay perspective, its occurrence during an existing contractor delay does not automatically make the two events concurrent.

This distinction matters because people often use the word “delay” to describe several different conditions. An activity can be late against its baseline date. Work can be progressing slower than planned. An RFI can remain unanswered beyond the contractual review period. A procurement item can arrive later than originally anticipated. Each condition may be important, but project delay usually requires another analytical step. We need to determine whether the event affected the path controlling the milestone under examination.

That is why credible concurrent delay analysis begins with causation rather than calendar overlap.

Both events must be tested against project completion

A useful way to examine concurrency is to ask a simple question about each delay event. If the first event had not occurred, would the second event still have delayed the relevant completion milestone during that period? Then reverse the question. If the second event had not occurred, would the first event still have delayed completion?

The wording is simple, although the actual analysis can become complicated. Imagine that permanent power is delayed by 30 calendar days and clearly controls the commissioning sequence. During those same 30 days, electrical rough-in slips by 12 working days but remains inside its available float. If the utility problem disappeared tomorrow, the rough-in path might still finish early enough to support the original completion date. In that scenario, the contractor problem may not independently create critical delay during the period being analyzed.

Now move forward one monthly update. The electrical subcontractor has continued to lose productivity. Its original float has been exhausted, and the electrical-room completion path now converges with the delayed permanent-power path. Both sequences feed energization and commissioning. At this point, the schedule is different. A contractor-responsible problem that was non-critical in May may become critical in June. Concurrency therefore may exist for part of the overall delay period even though it did not exist at the beginning.

This is an important point because construction projects rarely remain analytically clean for long. The critical path moves as work is completed, workarounds are introduced, procurement dates change, access becomes available, crews are reassigned, and schedule logic is revised to reflect the current execution plan. Good delay analysis follows those changes through appropriate time periods instead of forcing the entire project into one static explanation.

AACE’s forensic scheduling guidance recognizes this problem by addressing the frequency, duration, and chronological placement of analysis intervals when concurrency is evaluated. That technical language reflects something field teams experience every month. A delay that controls the project in one update may lose its controlling position in the next, while a previously secondary problem becomes critical.

For this reason, statements such as “the owner delayed us for three months” or “the contractor was already late during that entire period” require further investigation. They may ultimately prove correct, but the schedule should demonstrate when the delay began affecting completion, how long that effect remained critical, and whether another independent delay was producing the same controlling effect during the same relevant period.

Why concurrency can disappear when the schedule is examined properly

One of the most revealing exercises in delay analysis is to trace the alleged concurrent events through successive schedule updates. A dispute that initially appears to involve two simultaneous critical delays often looks quite different once the analyst studies float, logic, progress, data dates, and path movement month by month.

Consider our project again. In April, the permanent-power path has five days of float and electrical rough-in has 22. In May, delayed utility coordination consumes the remaining float on permanent power and begins moving to substantial completion. Electrical rough-in loses another four days but still has 18 days available. By the June data date, the utility issue remains unresolved while electrical productivity deteriorates sharply. Rough-in has now consumed its remaining float and is approaching the same energization milestone. By July, permanent power has finally been released, but unfinished electrical work prevents energization from proceeding.

If we view the entire April-through-July period as one block, both parties can point to genuine problems and claim the other was responsible for the late completion. A more disciplined analysis reaches a more useful conclusion. The owner-side event may have controlled the earlier period. A period of genuine concurrency may have developed later when both independent paths were critical. After permanent power became available, the contractor’s unfinished work may have become the sole controlling delay.

The exact result depends on the project records, the contract, the quality of the schedules, and the delay-analysis methodology being used. The broader principle remains sound. Concurrency can begin, end, disappear, or reappear as project conditions change.

Modern scheduling platforms make it easier to examine these changes, although software cannot decide causation by itself. Primavera P6 remains widely used for complex CPM scheduling, and Oracle continues to update the platform. Its 2026 releases include a redesigned interface, while Oracle Primavera Cloud has expanded schedule health-check settings, risk-to-activity visibility, dashboards, and other project-control features. These tools can improve access to schedule information and help teams detect developing problems earlier, but an analyst still has to understand why a path became critical and whether the schedule data is reliable.

That distinction between calculation and judgment is central to concurrent delay analysis. P6 can calculate dates and float based on the network it is given. It cannot determine whether a logic revision made during an update reflects a genuine change in construction sequencing or an attempt to reshape the historical record. It cannot decide whether slower production was an independent contractor delay or reasonable pacing behind an existing owner delay. It cannot read meeting minutes, RFIs, procurement correspondence, daily reports, and field photographs and determine whether they support the story shown in the schedule.

Those questions become much more important as a project moves from routine schedule management into delay analysis.

In the next section, we will reconstruct the critical path itself and examine why the path shown in the baseline schedule may be very different from the path that actually controlled completion when the disputed events occurred.

Reconstructing what the critical path actually was

The critical path is a condition in time, not a permanent line

One of the most common mistakes in delay discussions is treating the critical path shown in the approved baseline schedule as though it remains fixed for the life of the project. The baseline is essential because it records the contractor’s original plan and establishes the logic, durations, sequencing, and milestone expectations against which later performance can be measured. It does not freeze the critical path in place. Once construction starts, the network responds to actual progress, procurement performance, access conditions, design development, subcontractor productivity, and thousands of smaller decisions made in the field.

Consider the project we have been following. At baseline, the longest path may run through structural completion, enclosure, electrical rough-in, permanent power, startup, and commissioning. Three months later, the structure could be ahead of plan while switchgear approval has slipped. A month after that, the switchgear issue may have been recovered, but controls integration or owner training may become the controlling sequence. The contractual completion date has not changed, yet the path most likely to determine whether that date will be achieved can move several times during construction.

This is why a delay analyst cannot responsibly open the baseline schedule, identify the original critical path, and use it as the sole measure of an event that occurred many months later. The more useful question is what sequence controlled completion immediately before, during, and after the alleged delay. Contemporaneous monthly schedule updates are usually the best starting point because they show the project as it was understood at successive data dates. When properly prepared, they capture completed work, remaining durations, revised forecasts, current logic, and emerging constraints.

On a well-managed project, that evolving record tells a story. An activity with 25 days of total float in March may have only eight days remaining in April. In May, it may become critical because another activity finishes late or a successor duration increases. By June, the original problem may have been resolved, yet a downstream testing sequence could now control substantial completion. These changes are normal. The concern arises when schedule updates fail to explain them, or when the logic changes dramatically without support from the actual construction plan.

For concurrent delay analysis, the timing of those changes is crucial. If an owner event affects a path that does not become critical until several weeks later, the beginning of the event and the beginning of critical delay may be different dates. Likewise, a contractor problem can exist for months without delaying project completion until its available float is exhausted. The event history and the critical-path history must therefore be examined together.

Why contemporaneous updates carry so much weight

Imagine that the project team is now reviewing three consecutive schedule updates. The April update shows permanent power as an important activity, but it still has several days of float. The owner’s approval process is moving slowly, although the project retains enough schedule flexibility to absorb a modest delay. Electrical rough-in has considerably more float and is progressing close to plan.

By the May update, the situation has changed. The approval needed to support permanent power has not been completed, and the remaining float on that path has disappeared. The forecast for energization begins to move. Substantial completion also moves because startup, integrated systems testing, and commissioning remain tied to energization through valid CPM logic. At this point, the owner-related issue has become a critical schedule event even though it began earlier.

The June update tells a different story. Permanent power remains late, but electrical rough-in productivity has fallen sharply. Several electrical rooms have missed planned completion dates, remaining durations have increased, and the rough-in path has almost no float left. Both sequences now feed the same energization and testing work. The project may therefore be entering a period where two independent delays are capable of affecting the same contractual milestone.

This type of month-by-month reconstruction is far more persuasive than taking the final schedule at the end of the project and trying to reason backward from it. Final schedules are useful, but they contain the cumulative effects of hundreds of earlier decisions. Contemporaneous updates give the analyst a series of snapshots showing what the project team knew and forecast at the time. When those updates were regularly submitted, reviewed, discussed in progress meetings, and supported by narratives, they can provide a much stronger foundation for determining when criticality changed.

Schedule narratives are particularly valuable here. A good narrative explains why completion moved, which paths were controlling or near critical, what major logic changes were made, and what risks the contractor expected during the next reporting period. If a June schedule suddenly shows electrical rough-in as critical but the accompanying narrative never mentions electrical productivity, the analyst should investigate. If progress meeting minutes from the same period repeatedly discuss manpower shortages and missed electrical-room dates, those records may help explain the change. If neither the schedule nor the contemporaneous records support the later claim, the position becomes harder to establish.

The quality of monthly updates therefore affects much more than routine reporting. Each accepted update can become part of the factual record used later to understand how delay developed. For contractors, owners, and construction managers, disciplined schedule updating is one of the least expensive forms of future dispute prevention.

What to examine inside a CPM schedule

When reconstructing the controlling path, an experienced scheduler looks beyond a printed critical-path report. The first step is usually to confirm the data date and determine whether actual progress has been entered consistently. Actual starts and finishes should correspond reasonably with daily reports, meeting records, and other project documentation. Remaining durations deserve close attention because an activity that was originally planned for 20 days may show 35 days remaining after weeks of poor production. That change can materially alter the forecast even if the network logic has not changed.

Total float trends are also important, although float should never be viewed in isolation. A path moving from 30 days of float to 15, then five, then zero is telling the analyst that the available schedule flexibility is being consumed. Near-critical paths deserve particular attention because they can become controlling with only a small change in progress or sequencing. On large projects, several paths may sit within a narrow float range, which makes a simple “critical versus non-critical” classification less useful than understanding the group of paths that can realistically influence completion.

Logic changes require even closer scrutiny. Relationships may legitimately change because the construction sequence changes, access becomes available earlier, work is resequenced, or a recovery plan is implemented. Those revisions should have a clear operational explanation. When predecessors are removed, new constraints appear, calendars change, or activities are reconnected during a disputed period, the analyst needs to understand why. A technically correct CPM calculation can still produce a misleading result if the underlying network no longer reflects the way the work was actually being executed.

Constraints deserve similar care. Hard constraints can override normal network calculations and sometimes hide the schedule behavior the analyst is trying to understand. Out-of-sequence progress can also affect path calculations depending on the scheduling settings and methodology used. The goal is not to search for a single software field that proves responsibility. The goal is to reconstruct the most credible picture of what controlled completion at each relevant point in time.

That reconstruction often changes the direction of the entire concurrency discussion. A party may begin with a persuasive calendar showing two delays overlapping for 50 days. After examining the monthly CPM updates, the analyst may determine that one event was critical for the first 20 days, both were independently critical for the next 15, and the second event controlled the remaining period. The original 50-day concurrency argument then becomes a much more precise discussion of separate windows and different causes.

That level of precision is where serious delay analysis begins. It also prepares us for the more difficult questions that follow, because criticality alone does not settle every concurrency dispute. Float consumption, pacing, and near-critical paths can create a grey area where the schedule mechanics are clear but the interpretation is not.

Float, pacing, and the grey zone between delay and concurrency

Concurrent delay becomes more difficult when the analysis moves beyond obvious critical activities. On many projects, the important argument is not whether two events occurred at the same time. It is whether one event was consuming available float, whether another event had already placed a ceiling on achievable progress, and whether a near-critical path was becoming capable of driving completion. These conditions are common on complex projects because construction rarely proceeds along one isolated critical chain. Several paths often move within a few days or weeks of each other, particularly during MEP completion, energization, startup, commissioning, and turnover.

The distinction matters because responsibility can change as float disappears. A delay that initially has no effect on substantial completion may become critical later. A contractor can also intentionally slow work behind an existing controlling delay without necessarily creating an independent delay of its own. This is where CPM mathematics must be interpreted alongside what the project team was actually doing in the field.

When one delay consumes float before another becomes critical

Return to the electrical example from the previous sections. Assume permanent power is forecast 20 working days late because of an unresolved owner-side approval. The path through permanent power has already exhausted its float and is controlling the forecast completion date. At the same time, electrical rough-in is progressing slowly, but that sequence begins the reporting period with 15 working days of positive float.

During the first week, poor electrical production consumes four days of that float. During the second week, another five days disappear. By the middle of the following reporting period, very little schedule flexibility remains. Nothing about the contractor’s production problem is trivial. Management should be addressing it, and the contractor may ultimately become responsible for critical delay. Yet the mere consumption of float does not mean that every day of slow production immediately delayed substantial completion.

This distinction becomes especially important in retrospective claims. Looking backward from a late project, it is tempting to classify every activity that eventually became critical as though it had been critical from the moment the underlying problem began. CPM schedules do not work that way. Float provides a measurable degree of scheduling flexibility, and the timing of its consumption matters. An activity can be ten days late against a baseline date and still have enough remaining float to avoid delaying the contractual milestone.

Consider what happens next. The owner-side permanent-power problem remains unresolved for another ten working days. During the same period, the electrical rough-in path consumes its final six days of float. At that point, both paths may begin influencing the same downstream energization sequence. The analytical question changes. We are no longer dealing simply with a critical owner delay and a contractor problem sitting safely inside float. We may now have two independent paths that can each affect completion.

This is one reason a blanket statement such as “the delays were concurrent for the entire month” can be misleading. The first portion of the month may have involved one controlling delay while the second portion involved two. If the analysis period is too broad, those distinctions disappear.

Float also raises contractual questions that should be treated carefully. Project teams sometimes speak about “owning the float” as though float were a physical asset assigned permanently to one party. Contract language varies considerably, and some specifications address float ownership directly while others do not. From a scheduling standpoint, the more immediate question is often simpler. How much float existed when the event occurred, how was it consumed, and when did the affected path begin influencing the completion milestone? Establishing those facts first usually produces a more reliable discussion of responsibility and entitlement.

AACE’s forensic scheduling guidance similarly treats criticality, near-criticality, float consumption, concurrency, and pacing as connected analytical issues rather than isolated calculations. Its guidance recognizes that the duration of the analysis period and the historical rate of float consumption can affect how near-critical paths are evaluated.

Pacing can look like contractor delay

Pacing is one of the most misunderstood conditions in a concurrent delay analysis. It occurs when a party reduces the pace of its own work because another controlling delay has already limited how quickly the project can advance. The concept sounds simple, but distinguishing legitimate pacing from an independent contractor delay requires careful examination of the schedule and contemporaneous records.

Suppose permanent power cannot be available for another six weeks because of an owner-responsible issue. The contractor originally planned to complete several electrical rooms four weeks before energization. Once the permanent-power delay becomes clear, the contractor decides there is little value in maintaining overtime and weekend shifts to preserve that original four-week gap. It reduces overtime, redistributes electricians to other areas, and plans to complete the rooms closer to the revised energization date.

Months later, a delay analysis shows that electrical-room completion occurred substantially later than the baseline schedule. If the dates are examined without context, the owner may argue that the contractor had its own overlapping delay. The contractor may respond that it deliberately paced its work because the delayed power milestone had already established the earliest meaningful date for energization.

The difference can be significant. If the contractor was genuinely capable of completing the electrical rooms on time but consciously reduced its pace in response to an existing critical delay, treating that slowed work as an independent concurrent delay may misstate what happened. If the contractor was already suffering from manpower shortages, procurement failures, poor productivity, or subcontractor problems before the parent delay arose, calling the situation pacing may be equally misleading.

Good pacing analysis therefore asks what was happening before the alleged pacing began. Was another independent delay already present? Did the contractor have the resources and practical ability to maintain its original production rate? Did the project records show a conscious decision to slow or resequence work because another delay had removed the need for earlier completion? Could the contractor reasonably have resumed normal production if the controlling delay had suddenly been resolved?

Contemporaneous evidence is particularly valuable. Meeting minutes may record a decision to reduce overtime until permanent power is available. Look-ahead schedules may show deliberate resequencing. Manpower reports may demonstrate that workers were transferred to productive work elsewhere rather than simply disappearing from the project. Correspondence may show that the contractor notified the owner that work was being paced behind an existing delay. Without records of this kind, a pacing argument made for the first time during a claim can be difficult to distinguish from an attempt to explain poor performance after the fact.

The subject remains highly relevant in current delay practice. At AACE International’s 2026 Conference & Expo, a technical session devoted specifically to pacing examined situations where a party slows work behind a critical delay, the risk that such pacing may be perceived as concurrent delay, and the need to evaluate parent delays and near-critical paths. The continuing professional attention is understandable. Modern project teams have more schedule data than ever, yet interpreting why production changed still requires judgment and credible contemporaneous documentation.

Why near-critical paths deserve more attention

Most project executives understand the critical path in broad terms, but fewer routinely watch the paths immediately behind it. That can become a serious weakness during periods of delay because a path with a small amount of float can become critical much faster than the monthly reporting cycle suggests.

Suppose the current longest path runs through permanent power and commissioning with zero total float. A second path through fire alarm completion has four working days of float, while a third path through controls programming has seven. The schedule report may technically classify only the first path as critical. From a management perspective, however, all three deserve attention. A missed inspection, slower testing production, or delayed software integration could consume the remaining float on either secondary path within days.

This is particularly relevant to concurrent delay. Imagine that the owner-caused permanent-power delay persists while fire alarm work begins losing time because of a contractor coordination problem. For the first portion of the reporting period, the fire alarm path has enough float to remain non-critical. Once that float is exhausted, it can become an independent controlling path. If the analyst looks only at the schedule status on the first or last day of a long analysis window, the transition may be missed.

Near-critical paths are also important because complex construction projects increasingly converge near completion. During early structural work, one dominant path may be relatively easy to identify. During final MEP work and commissioning, numerous systems must be ready within a narrow window. Electrical power, controls, life safety, elevators, building automation, equipment startup, inspections, training, corrective work, and turnover documentation can each become influential. A project that appears to have one critical path in February may effectively have several competing near-critical paths by June.

Modern scheduling systems can help identify these emerging risks. Primavera Cloud, for example, includes configurable schedule-health checks and project-level schedule-health metrics, while CPM calculations continue to rely on activity relationships, constraints, dates, and the project data date. These tools make it easier to surface problematic conditions, but no health score or dashboard can replace path analysis. A schedule may pass automated checks and still tell an incomplete story about causation.

For project managers, the practical response is to stop treating float as a comfortable reserve that can be ignored until it reaches zero. A path that loses float consistently over several updates is giving an early warning. Watching that trend can identify potential concurrency before it develops into a contractual dispute. It also gives the project team a better opportunity to recover the work while the problem is still manageable.

For a forensic analyst, the same history helps establish when responsibility changed. The record may show an owner-controlled path first, a period where a contractor path moved into criticality, and a later period where the original owner issue disappeared while the contractor problem remained. That sequence is far more informative than saying both parties were “late at the same time.”

Concurrent delay is therefore rarely solved by one float value or one critical-path report. The stronger analysis follows the changing relationship between events, paths, float, and actual project behavior. Once those mechanics have been reconstructed, the next question is whether the documentary record supports the schedule story. That is where daily reports, RFIs, submittals, procurement records, meeting minutes, notices, and schedule narratives begin to carry much more weight.

The evidence that makes or breaks a concurrent delay analysis

A CPM schedule can show when a path became critical, how float changed, and which activities were forecast to control completion. It cannot, by itself, establish the full factual history of why those conditions developed. That distinction becomes especially important in concurrent delay disputes, where two parties may rely on the same schedule while telling very different stories about what caused the delay and whether each event was truly independent.

Strong delay analysis therefore combines schedule mechanics with the contemporaneous project record. The analyst should be able to move from an activity in the CPM network to the documents that explain what actually happened in the field. When that connection is missing, the schedule may still be mathematically correct, but the explanation behind it becomes much harder to defend.

The schedule alone is not enough

Consider the permanent-power delay from our running example. The schedule shows that energization moved by several weeks and that commissioning shifted accordingly. That establishes the timing of the schedule effect, but the analyst still needs to determine why permanent power moved. Was the delay caused by an owner design decision, a late utility response, incomplete contractor work, unresolved inspection requirements, or some combination of these conditions?

The answer may be found across several types of records. RFIs may show when technical questions were first raised and answered. Submittal logs may establish whether equipment or design information was submitted on time. Meeting minutes may document repeated discussions about unresolved utility coordination. Daily reports may confirm when rooms became available, when crews were mobilized, and whether physical installation was actually ready for the next step. Procurement logs may reveal whether equipment availability was an independent constraint. Correspondence and formal notices may show when the parties first recognized that the issue could affect project completion.

The same approach applies to the contractor-side delay. If electrical rough-in is alleged to have become independently critical, the analysis should examine manpower records, productivity trends, inspection results, subcontractor correspondence, material availability, and short-term planning records. A schedule activity showing an extended remaining duration may be accurate, but the reason for that extension matters. The cause could be low manpower, late access, unresolved design, failed inspections, missing materials, or deliberate pacing behind another controlling event.

This is where project records either support the schedule story or begin to contradict it. A contractor may argue that electrical work was paced behind an owner delay, while daily reports show that staffing had already fallen well before the owner issue became critical. An owner may argue that a late decision had no schedule effect, while contemporaneous meeting minutes repeatedly identify the decision as the controlling obstacle to energization. Good analysis does not choose one document and treat it as decisive. It compares the available evidence and asks whether the records tell a consistent story.

The most persuasive delay files are usually built during construction rather than assembled for the first time after substantial completion. Monthly schedule updates, narratives, notices, daily reports, look-ahead schedules, procurement records, and meeting minutes should reinforce one another. When they do, the project team has a much stronger basis for resolving schedule issues before they develop into formal claims.

Build the chronology before arguing responsibility

One of the most effective ways to analyze concurrent delay is to construct the factual chronology first and assign responsibility only after the sequence of events is clear. This reduces the tendency to approach the records with a predetermined conclusion.

A useful chronology begins with the date an event first arose, then tracks how it developed. For each event, the analyst should identify the affected activity or path, the float available at the time, the relevant data date, and the point at which the event began to influence a contractual milestone. The chronology should also capture mitigation efforts, notices, changes in sequencing, and the eventual resolution of the issue.

For example, the permanent-power chronology might show that a design clarification was requested on April 10, the issue remained unresolved through the April schedule update, float was exhausted by May 6, and the forecast energization date began moving in the May update. The contractor then resequenced some downstream work and recovered several days, but permanent power remained on the controlling path through June.

The contractor-side electrical chronology might show that production began slipping in late April, though the path still had more than two weeks of float at that point. Manpower declined during May, several rooms missed planned completion dates, and the remaining float was consumed by mid-June. Only then did the electrical path become capable of delaying energization independently.

Once these two chronologies are aligned against the same reporting periods, the concurrency question becomes more precise. The project may show an owner-controlled period first, followed by a shorter period of true concurrent critical delay, then a later period where the contractor delay continues after the owner event has been resolved.

This method is more useful than beginning with a broad statement such as “both parties delayed the project during May and June.” It also gives project executives a clearer picture of how responsibility changed over time. Even when a claim eventually requires legal interpretation, a well-built chronology makes the underlying schedule facts easier to understand.

The chronology does not have to be complicated. In many cases, a simple event matrix can be extremely effective. Each row can identify the date, relevant record, affected activity, float condition, critical-path status, and observed impact on the milestone. The value comes from forcing the analysis to connect the documentary evidence with the CPM network.

Why rewriting history destroys schedule credibility

Schedule credibility can deteriorate quickly when logic, constraints, durations, or actual dates are changed after a dispute develops without a clear contemporaneous explanation. Not every schedule revision is suspicious. Construction plans change constantly, and legitimate updates often require logic revisions, revised durations, new activities, and changes to sequencing. The concern arises when historical schedule behavior is altered in ways that appear designed to support a later position rather than reflect how the project was actually managed.

Suppose an update originally showed electrical rough-in with 15 days of float during the early portion of an owner-caused delay. Months later, after a dispute emerges, a revised file is produced with additional logic ties that make electrical work appear critical much earlier. The new logic may be technically possible, but the analyst should ask whether that sequence was actually being followed at the time. Was it reflected in contemporaneous look-aheads? Was it discussed in progress meetings? Did the field team treat those activities as controlling? If not, the later revision may have limited evidentiary value.

The same concern applies to hard constraints added after the fact, deleted relationships, unexplained calendar changes, modified actual dates, or unusually large adjustments to remaining durations. Each change can affect float and critical-path calculations. If the revision is legitimate, it should be traceable to a real change in execution or to correction of an identified scheduling error. If it cannot be explained, the credibility of the analysis suffers.

This is why disciplined schedule governance matters throughout the project. Contractors should preserve submitted schedule files, maintain update logs, document major logic changes, and explain important forecast movements in the monthly narrative. Owners and construction managers should review those changes while the project is active rather than waiting until a dispute develops. A schedule update that is accepted without meaningful review can become difficult to challenge much later, particularly if it was repeatedly used for project decision-making.

Technology can help preserve this audit trail. Modern project controls platforms increasingly support version history, collaborative reviews, change tracking, schedule-health checks, and integrated reporting. These tools improve transparency, but they do not eliminate the need for professional judgment. A schedule can be fully archived and still contain weak logic. A dashboard can identify excessive constraints but cannot decide whether a particular constraint was contractually justified. The record is useful only when the underlying schedule reflects how the project was actually planned and executed.

For concurrent delay analysis, credibility often matters as much as complexity. A simple schedule with consistent updates, clear narratives, and reliable field records can be more persuasive than an elaborate retrospective model built years later. When the contemporaneous record aligns with the CPM analysis, the explanation becomes much easier to follow. When the schedule and the project documents contradict each other, even technically sophisticated delay models can struggle to overcome that inconsistency.

By the time a project reaches a formal dispute, most of the important evidence has already been created. The quality of that evidence depends on what the team documented while construction was still underway. That is why good schedule management is also good claims prevention. The project team that understands its critical paths, preserves its records, and explains major schedule movements each month is in a far better position to resolve concurrency questions before they become expensive arguments.

Managing concurrent delay before it becomes a claim

Concurrent delay is easier to analyze when a project team has been managing the schedule properly all along. By the time attorneys, claims consultants, or forensic schedulers are asked to reconstruct events months or years later, many opportunities to clarify what happened have already passed. Memories fade, project personnel move on, field conditions change, and the meaning behind schedule revisions becomes harder to recover. The best time to understand a developing delay is while the affected work is still underway and the people who made the decisions are still involved.

This does not mean every project problem should be treated as preparation for litigation. That approach can damage working relationships and encourage defensive project management. A better practice is disciplined contemporaneous management. When a significant event emerges, the team should identify what schedule path it affects, determine how much float remains, evaluate whether completion is threatened, record mitigation efforts, and continue updating the CPM schedule to reflect actual conditions. Doing this consistently helps projects solve problems sooner and creates a reliable record if disagreements later develop.

What contractors should do while the events are happening

Contractors should resist the temptation to wait until a delay becomes severe before analyzing its schedule effect. An unanswered RFI, delayed design decision, access restriction, late owner-furnished item, or utility problem may initially have float. That does not make it irrelevant. The important task is to watch how the affected path develops through successive updates and determine whether available float is being consumed faster than expected.

The monthly CPM update should remain the central record, but monthly reporting alone may be too slow for a rapidly developing problem. A contractor that identifies a potentially critical event should follow the affected sequence through look-ahead schedules and short-term planning. If the delay begins affecting critical or near-critical work, the project team should document the condition promptly and connect it to specific schedule activities rather than relying on broad statements that “the project is being delayed.”

Mitigation should receive the same level of documentation. Suppose an owner-side approval delays permanent power, but the contractor resequences ceiling work, moves crews to another building area, advances testing documentation, or accelerates another path to reduce the eventual effect. Those actions matter. They help demonstrate how the contractor responded to the event, and they may explain why the final completion impact is smaller than the duration of the original disruption.

Contractors also need to be candid about their own performance. A persuasive delay position becomes much weaker when serious subcontractor or production problems are hidden from schedule updates and later emerge through daily reports or meeting minutes. A contractor can experience an excusable owner delay while also experiencing internal performance problems. The purpose of CPM analysis is to determine when and how those conditions affected completion, not to create a perfect historical narrative for either party.

What owners and construction managers should examine

Owners face a different risk. A contractor may identify an owner-responsible event and assume that the full duration of that event automatically supports an equivalent extension of time. The owner should evaluate the schedule effect carefully rather than focusing only on whether the underlying event occurred.

If a design clarification takes 30 days longer than anticipated, the first question is whether the affected activity was critical during those 30 days. The next question is whether another independent path was already controlling completion. The owner should also examine available float, the contractor’s progress on related work, mitigation opportunities, logic changes, and whether the schedule being used for the analysis accurately reflects the condition of the project at the relevant data date.

This is particularly important when a project contains several near-critical paths. An owner may correctly determine that its delay affected the critical path while overlooking a contractor problem only a few days behind it. Conversely, an owner may identify contractor underperformance somewhere on the project and describe it as concurrent without establishing that the underperforming work independently delayed the same contractual milestone. Neither conclusion should be reached simply because both parties experienced problems during the same month.

Independent schedule review can be valuable on large or troubled projects because it separates progress reporting from critical-path interpretation. The review should examine the schedule as a dynamic network rather than a collection of milestone dates. Float trends, remaining durations, logic revisions, constraints, actual progress, and changes in the longest path should all be examined together. When this happens every month, potential concurrency can often be identified while recovery options are still available.

There are five practical questions worth asking whenever someone states that a project has concurrent delay:

1. What are the independent delay events being compared, and what caused each one?
2. Which CPM activities, paths, and contractual milestones did each event affect?
3. Was each event independently capable of delaying the relevant milestone during the same meaningful period?
4. What float existed when each event began, and when was that float actually exhausted?
5. Do the contemporaneous schedule updates and project records support the explanation being offered?

These questions do not replace a formal delay-analysis methodology. They provide a useful screening test that can prevent a project team from turning every overlapping problem into a concurrency argument. If the answers are unclear, the schedule usually needs further examination before strong conclusions are reached.

How Leopard Project Controls can help with complex delay and concurrency issues

Concurrent delay analysis demands more than the ability to operate scheduling software. The work requires an understanding of CPM logic, changing critical paths, float behavior, construction sequencing, schedule specifications, contemporaneous records, and the practical way projects are executed in the field. It also requires restraint. A useful scheduling consultant should follow what the project record demonstrates rather than begin with the answer a particular party hopes to establish.

Leopard Project Controls provides CPM scheduling and project controls services for contractors, owners, developers, and public-sector project teams across the United States. Its work includes Primavera P6 and Microsoft Project scheduling, baseline schedule development, progress updates, schedule narratives, Time Impact Analyses, delay assessments, extension-of-time documentation, schedule compliance, earned value reporting, executive dashboards, and owner-side schedule review. The company also supports federal and public projects that must meet scheduling requirements associated with agencies such as USACE, NAVFAC, VA, and DOT.

In a developing delay situation, that experience can be applied before the disagreement becomes a formal claim. Schedule updates can be reviewed to identify when a path became critical, how float changed, whether logic revisions are reasonable, and whether an alleged delay is actually affecting completion. Time Impact Analysis can be used where the contract and circumstances call for a prospective or contemporaneous evaluation of a delay event. For owners, independent schedule review can help test a contractor’s explanation against the underlying CPM network. For contractors, disciplined schedule development and updating can improve the credibility of time-extension requests and delay documentation.

The firm is led by Seyar Azadani, whose qualifications include PMP and PMI-SP credentials, Florida Certified General Contractor licensure, more than 20 years of construction scheduling and project controls experience, and an M.S. in Construction Management from New York University. Leopard Project Controls’ leadership experience encompasses more than $10 billion in project value across federal, commercial, infrastructure, mission-critical, education, and other capital construction sectors. The firm also lists federal contracting registrations and small-business certifications that support work across public and private markets.

For concurrent delay work specifically, the practical value lies in connecting schedule analysis to the construction record. That can involve examining successive P6 updates, longest-path movement, total float trends, activity logic, remaining-duration changes, schedule narratives, delay events, and supporting project documentation. The objective should be a clear explanation of what affected completion and when, supported by a schedule that another experienced reviewer can follow.

This type of analysis is often most valuable before positions become entrenched. When an owner and contractor have competing explanations for a developing delay, an early review of the contemporaneous CPM record can reveal whether the disagreement involves genuine concurrency, sequential delays, float consumption, pacing, or separate problems that happened to occur at the same time. That distinction can influence recovery planning as much as eventual time entitlement.

Concluding remarks

Concurrency is established through causation, not coincidence

Return to the project meeting where our discussion began. Permanent power is late because of an owner-side issue. Electrical rough-in is also behind plan. The dates overlap, and substantial completion is slipping. Calling the situation concurrent delay may feel intuitive, but the schedule analysis developed throughout this article shows why that conclusion needs to be earned.

During the first period, permanent power may be controlling completion while electrical rough-in still has substantial float. Later, the contractor path may consume that float and become independently critical. For a limited period, both paths may genuinely influence the completion milestone. Once permanent power is released, unfinished contractor work may become the sole controlling problem. What sounded like one continuous concurrent delay at the progress meeting may actually contain several distinct periods with different schedule conditions.

That distinction has practical consequences. It can affect extension-of-time discussions, assessment of liquidated damages, evaluation of compensable delay, mitigation decisions, recovery planning, negotiations, and the credibility of any later claim. Those consequences are too important to base on the visual overlap of two schedule bars.

Reliable analysis starts with contemporaneous CPM schedules and follows the project as conditions change. It examines critical and near-critical paths, float consumption, logic, remaining durations, actual progress, pacing, and the documentary record surrounding the events. The schedule provides the analytical framework, while project records explain what was actually happening behind the activities and dates.

The broader lesson extends beyond disputes. A well-maintained schedule is one of the project’s most useful management records. When teams update it honestly, explain major changes, preserve historical files, and investigate developing critical paths early, they gain something more valuable than a stronger claim position. They gain the ability to understand delay while there is still time to do something about it.

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