SCHEDULE VALIDATIONS AND AUDITS – Timing, Methodology and Conclusions – (Part 3 )


Validation occurs when the initial or revised baseline schedule is submitted prior to the start of any construction field-site work, with the possible exception of mobilization, site preparation, ordering of long-lead time equipment or materials, permits, excavation, and installation of in-ground site utilities.

Validation is an extensive process and can be time consuming both initially and after each re-submittal of the proposed baseline ‘planned’ construction schedule until a valid baseline schedule is accepted by all significant stakeholders: Owner, Contractor, Subcontractors, Suppliers, Financing entities, and Permitting agencies.

Before a complete Validation process is performed an Appraisal is done to determine if the requirements for Validation are in place.

Auditing must occur several times during the execution phase of the Project’s life cycle. The first such audit should be done between the 15 and 20 percent completion points to recheck the initial duration, resource, and productivity estimates. This audit may coincide with the completion or near completion of the excavation and installation of the in-ground utilities. At that point the major ‘unknown unknowns’ and risks are resolved. In consideration of the actual results, a revised Work Plan and development of a new Baseline Schedule in accordance with the known conditions and better estimates can be made.

A second time for auditing and reappraisal is when the erection of structures are ‘complete’ and the finishing work done by multiple specialty trades can begin. At this point a new ‘estimate to complete’ and ‘estimate at completion’ can be made.

The final time when an Audit is desirable and/or required is at the completion of the Project to document the ‘as-built’ schedule.  If Validation and Auditing are performed, analysis of schedule related claims and their resolution becomes a quick process.


There are many facets and procedures used to conduct schedule Validations and Audits. Basically, the electronic database used to develop the proposed schedule is dissected and decomposed to reveal all of the parameters used. In addition, a 100% cross-check is made between the Work Package activity logic diagrams and the data in the electronic database, as they must be in absolute agreement. All input data, constraints, etc., must be the same as that used by the electronic program that produces the schedules, resource histograms, and Earned Value charts.

Typically, some of the Validation and Auditing efforts are:

  • Review, evaluate and critic the Scope {aka Work} Breakdown Structure;
  • Evaluate estimates of resources, schedule activity durations, and earnings;
  • Check the logic: both mandatory and preferential on the Network Diagrams;
  • Analyze the work plan strategy, means, methods, and assumptions;
  • Review date constraints: milestones, external, and performance duration;
  • Review resource, earnings, production, and space restraints;
  • Review resource calendars;
  • Check on-site long-lead item requirements: submittal/approval, fabrication or manufacturing, shipping, customs processing, delivery to site, Inspection, acceptance, inventory, and storage;
  • Perform database versus input data validity / cross-check;
  • Review linear schedules of trades and materials;
  • Review the submittal register and schedule: completeness and the submittal review loading histogram;
  • Review the use of contingencies for activities, work-packages, and milestones;
  • Review time and earning-funding reserves – buffers;
  • Review earned value graphs: earnings-funding, man-days, material placements, trade performance/productivity;
  • Analyze schedule and earnings performance indexes after 25% of the Project’s duration;
  • Evaluate performance-to-date and estimated forecast at completion.


Construction work scheduling has become a complex process as it attempts to model the real world of building a project of high quality and reasonable profitability in today’s environment of limited resources, both material and skilled workers, on time, and within budget.

Consequently a schedule becomes vulnerable to inappropriate practices, misuse, abuse, and gamesmanship.

Hence to attain a reasonable, rational, realistic, and valid work plan and schedule for both the owner and contractor, an experienced independent person or team should validate the baseline schedule and periodically audit the project’s progress and performance.

Contractors and Owners have too much invested to ignore the benefits of an independent Baseline Validation and periodic Audits. The validation expense is nominal: the Return-on- investment is large.


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