Construction Delays

By Mark F Nagata, William A Manginelli, Scott Lowe and Ted J Trauner

Construction Delays, Third Edition, provides the latest specialized tools and techniques needed to avoid delays on construction projects. These include institutional, industrial, commercial, hi-rise, power and water, transportation and marine construction projects. Most other references provide only post facto construction delay analysis. This update includes 18 chapters, 105 sections and approximately 100 new pages relative to the second edition.

• Features greatly expanded discussion of the project management concerns related to construction delays, including a more comprehensive discussion of the development and review of the project schedule
• Offers a detailed analysis of the strengths and weaknesses of the most common construction delay approaches and how they should be properly deployed or avoided
• Includes significant discussion of the contract provisions governing scheduling, the measurement of delays and payments for delay
• Includes numerous real world case studies

• Language: English
• Publisher: Elsevier Science
• Release date: Sep 20, 2017
• ISBN: 9780128112434

Mark F Nagata

Mark is a recognized expert regarding the analysis of Critical Path Method (CPM) schedules. He’s a qualified expert witness. Mark was a contributing author and continues to provide updates and revisions to the AACE International’s (AACEi) Recommended Practice No. 29R-03 for Forensic Schedule Analysis (RP-FSA. He writes and speaks nationally and internationally on construction claim topics. Mark uses his expertise to help his client’s prepare, evaluate, and analyze delays, inefficiencies, acceleration, and damages on projects including transportation, power, medical, education, commercial, and high-rise buildings across the US and internationally.

Book preview

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Chapter One

Project Scheduling

Abstract

If we were to ask a contractor, a construction owner, or an architect or engineer if they plan their construction projects, undoubtedly they would respond in the affirmative. In the beginning, everyone has some form of a plan as to how the work will be executed.

Keywords

Project; schedule; plan; construction; delays; task

The Project Schedule

If we were to ask a contractor, a construction owner, or an architect or engineer if they plan their construction projects, undoubtedly they would respond in the affirmative. In the beginning, everyone has some form of a plan as to how the work will be executed.

Their plans might include some or all of the following elements:

• The tasks that must be performed

• The time required to perform each task

• The sequence that these tasks will be performed

• The subcontractors, trades, and numbers of workers that will perform each task

• The physical aspects of the project and the project site that might affect the performance of the tasks

• The availability of materials

While this list of typical plan components could be expanded, the concept is straightforward: each component represents an important consideration associated with the planning of a construction project.

A project schedule is a written, graphical, or computerized model of the project team’s plan for completing a construction project. Schedules emphasize the elements of sequence and time. The plan will typically identify the major work items (activities), the time (duration) needed to perform these activities, and the sequence (logic) of construction of these activities to complete the project.

At its most basic level, a project schedule will visually depict the intended timing of the major work items necessary to demonstrate how and when the project team will construct the project.

The project schedule should include the significant elements of the project sequenced in a logical order from the beginning of the project through its completion. In addition, the schedule should define specific time periods for each activity in the schedule. The sequencing and summation of the individual time elements will define the overall project duration.

The level of detail shown in a construction schedule will vary, depending on a number of different factors. To name just a few, those factors include the type of schedule used, the contract requirements, the nature of the work, and the contractor’s practices.

Overall, the project schedule should portray in a clear way the construction tasks that must be performed, the time allocated to each task, and the sequence of the tasks.

The Primary Purpose of a Project Schedule

Just as a bid is an estimate of the costs required to construct each piece of a project and the project as a whole, the project schedule is an estimate of the time required to construct each piece of a project and the project as a whole. A project schedule is a valuable project controls tool that is used by project managers to effectively manage construction projects. As noted earlier, the project schedule should include every major element of the construction project. In this manner, it should provide a complete picture of the project’s planned construction sequence from start to finish, forecasting when the project will complete. Additionally, if the project schedule is properly developed and updated throughout the duration of the project, it will provide periodic snapshots of the plan to complete the project as the project progresses and as the plan changes over time.

When the project schedule is properly updated and revised to reflect the current construction plan, it enables the project participants to measure and control the pace of the work, provides the project participants with reliable information to make timely decisions, and serves as the primary tool to evaluate the effect of changes and other potential delays on the project plan as these events occur.

Effectively depicting and communicating the construction plan

Successful contractors use project schedules to depict and communicate the construction plan to the owner, the owner’s representatives, the contractor’s subcontractors and suppliers, and other project participants. The development of the construction plan should be a collaborative process that includes the contractor and its subcontractors, and the owner and the owner’s team. Involving the subcontractors in the development of the construction schedule will significantly facilitate acceptance by the subcontractors of the overall approach to building the project. Additionally, incorporation of the subcontractors’ means and methods will give greater credibility to the project schedule as a tool that accurately depicts the planned construction activities, durations, and sequencing.

The planning effort is the first essential step to successful execution of a construction project. This is because the development of the construction plan requires the project manager, superintendent, and other key team members to determine and identify how the project will be constructed. Although a project’s planned sequence of construction may appear to be straightforward, there are many decisions that have to be made to develop a fully thought-out and comprehensive plan. Those decisions usually begin with identifying the project’s work scope. That work scope is broken down into more detail by area, location, trade, and individual work item. To accomplish each work item, the team has to agree on the most efficient and cost effective use of the available labor and equipment resources. This, in turn, drives the decision regarding how much time must be allotted to each work item. Additional considerations are the coordination of the individual work items and the use of subcontractors. Often, a contractor’s competitive advantage is derived from its ability to manage its resources and risk, and apply its means and methods in a manner that is more efficient and cost effective than its competitors.

Estimating the time needed to complete a specific operation or trade work element, such as foundations, steel erection, or roof installation, involves many considerations, including:

• Understanding the project and its unique elements

• Understanding the physical conditions under which the work has to be performed, such as location constraints and limitations, usage of the project during construction, climate, and the effect of these on the labor and equipment to be used

• Understanding the quantity and quality of the available labor resources

• Identifying the required materials, sources, and lead times

• Identifying the required and available equipment

• Understanding how the integration of these above factors affect the predicted productivity of an operation

• Incorporating predictable risks or events that could affect how long an operation or individual activities would take to complete

Once the contractor has a project schedule that it believes is an accurate representation of the construction plan, the contractor should share the schedule with the owner to demonstrate its plan and to inform the owner when it will need to perform its obligations, which may include the review and approval of shop drawings and submittals and inspection of the work. Effectively communicating the work plan to all parties involved is not only a sound project management practice, but it also promotes a culture of cooperation and partnering.

Additionally, a properly updated project schedule will also document changes in the contractor’s plan to complete the project. Successful contractors and owners know that, as a project progresses, they may encounter unexpected problems or issues. In response to these, the contractor may need to alter portions of its construction plan, such as its work sequence, crew sizes, and operating hours. Project schedules should be periodically updated to reflect the contractor’s then-current construction plan. These updates will provide snapshots of the contractor’s plan as it changes during the course of the project.

Track and measure the work

A project schedule that is properly and periodically updated throughout the life of the project will enable the contractor and owner to accurately track and measure the project’s progress. Using the project schedule for tracking and measuring occurs on at least two levels. In most instances, owners use the project schedule to track the contractor’s progress, keep the project stakeholders informed of the project’s status, and ensure that the contractor completes the project in accordance with the contract. Also, the project schedule includes activities representing the subcontractors’ agreed-upon scopes of work. As such, the contractor is able to track and measure the progress of its subcontractors to ensure that their work is completed in accordance with their subcontract agreements.

Timely decisions

In addition to tracking and measuring the project’s progress, a properly maintained project schedule will also enable the parties to identify and deal with unexpected issues as they arise. When a problem is encountered that may delay some element of the project, the project participants can use the project schedule as a tool to predict the effect of the delay on the completion of the overall project. In addition to predicting the effect of the problem, they can also decide on an appropriate course of action to deal with the problem, which may include accelerating the work, relaxing contract restrictions to more quickly advance the project, or deleting work items. This ability to predict and deal with a problem that may delay the project before it actually does so is perhaps a project schedule’s most valuable attribute. Most project managers can see and deal with problems as they occur. However, good project managers can also predict how problems today will affect the project in a month, in 6 months, and even farther in the future. Relying on the project schedule as a planning, scheduling, and management tool will enable project managers to more competently and reliably control and manage their projects.

Types of Project Schedules

A contractor can use many different types of schedules to depict its construction plan. Selection of the most appropriate scheduling technique depends on the size and complexity of the construction project, the preferences of the party preparing the schedule, and the scheduling requirements of the contract. The most common scheduling techniques used for construction projects are narrative schedules, Gantt Charts or bar charts, linear schedules, and Critical Path Method (CPM) schedules.

Narrative schedules

Narrative schedules are typically used on very small construction projects that have very few activities. A narrative schedule consists of a narrative description of the contractor’s planned construction sequence and is typically submitted prior to the start of work. For example, a narrative schedule may tell the owner that the contractor plans to work across the project site from east to west. In addition, in the narrative the contractor should also identify the number of crews it plans to use and how long it believes the work will take. The degree of detail in a narrative schedule will vary from project to project, but most narrative schedules range between one paragraph and two pages. When a narrative schedule is requested, the contract scheduling specification should identify the level of detail required. An example of a narrative schedule is shown in Fig. 1.1. The physical project as described in the narrative schedule is shown in Fig. 1.2.

Figure 1.1 Narrative schedule.

Figure 1.2 Example bridge project.

Gantt charts

A Gantt chart, also called a bar chart schedule, visually depicts the project’s major work activities in relation to time. A Gantt chart or bar chart schedule is a simple and straightforward depiction of the construction plan, showing the duration and timing of the work activities with the sequence of tasks implied. The major work items or activities are identified along the vertical axis, and time is tracked along the horizontal axis. The chart contains columns along the left-hand side of the page that identify the number and title of the major work activities, activity durations, and the activity start and finish dates. To the right of the columns are horizontal bars that represent the work activities described in the columns. The work activities are typically organized in descending chronological order, with the earliest work item in the first row, the next earliest work item in the second row, and so on. In addition to organizing the work items chronologically, they can also be grouped according to similar locations, phases, and so forth. A compilation of all of the horizontal bars should provide a visual representation of the work for the entire construction project. An example of a bar chart for a construction project is shown in Fig. 1.3.

Figure 1.3 Gantt chart or bar chart schedule.

Once work begins, the actual performance of the project can be tracked using the same chart. As the project progresses forward in time, the horizontal work bars that originally depicted when work was planned to begin can be compared to actual work bars that are drawn into the schedule as work progresses. These actual work bars can reflect progress and the actual start and finish dates of activities. If required, Gantt charts or bar chart schedules can be updated periodically throughout the project to show the status or progress of the work as of that time and be updated to forecast the timing and sequencing of the remaining contract work. The Gantt chart or bar chart schedule is typically used on smaller projects for which the relationships among the activities are obvious or easily recognized. A typical Gantt chart or bar chart schedule only summarizes the major work items and is usually only one to two pages long. It should be noted that bar charts can be very large and very detailed. If done correctly, they can be an acceptable method for scheduling the work, depending on the nature of the project.

Linear schedules

The Linear Scheduling Method is also referred to as Line of Balance scheduling. It is most effectively used to plan and manage construction projects that are repetitive or linear in nature, such as highway construction and pipeline and power line construction. A linear construction schedule is usually depicted as a graph with an X- and Y-axis. The entire project duration (time) starting from Day 0 to the end of the project is plotted along the X-axis, and the project’s scope of work is plotted along the Y-axis. Specific work locations along the length of the project are plotted from one end of the project to the opposite end, ascending from the lower limit of the X-axis to its upper limit of the Y-axis. The measure of production is typically represented as specific locations along the project and, depending on the type of construction project being depicted, the measure of production can be defined as stationing for highway and pipeline projects or floors for high-rise building construction. The schedule activities are usually represented as a line that starts at the X-axis and that extends upward toward the upper limit of the Y-axis that depicts performance of the schedule activity along the entire length of the project. The slope of the schedule activity line will represent the production rate of the schedule activity’s operation. Fig. 1.4 is an example of a linear schedule for a roadway project.

Figure 1.4 Linear schedule.

The major advantage that the linear scheduling method has over other scheduling techniques—e.g., a narrative schedule, Gantt chart, and CPM schedule—is that a linear schedule allows the user to easily track planned and actual production rates of individual schedule activities. When used on linear projects, such as roadway and pipeline projects, productivity is often an important factor in measuring efficiency, profitability, and, ultimately, success. However, the major weakness of this technique is that it does not identify the project’s critical path.

It should be noted that whether or not a project has a schedule, the project will always have a critical path. The inability of the linear scheduling method to identify the project’s critical path stems from the fact that the schedule activities are not linked to one another and, thus, the schedule cannot accurately correlate delays to the completion of the project to specific schedule activities in a cause-and-effect manner. One of the major reasons that many owners and contractors have chosen the CPM scheduling technique over the linear scheduling methods is the CPM scheduling technique’s ability to identify the critical path of the project. With the critical path defined, the owner and contractor are better able to manage the project with respect to time. Along with this is the benefit of being able to assign project delays to specific schedule activities and determine whether the contractor is entitled to additional contract time.

The use of linear schedules is quite rare these days.

Critical path method schedules

A CPM schedule is similar to a bar chart schedule in that it contains the work activities necessary to construct the project. However, the CPM schedule usually contains all of the project work items and connects or links those work activities to one another according to their planned sequence. The result is a network of interrelated activities that defines the various paths of work necessary to construct the project. The linking or interdependency of the work items is a major strength of CPM scheduling because it enables the identification of the critical path or the longest path of work through the network. The critical path predicts the earliest date that the project can be completed.

CPM schedules are the most frequently used scheduling technique for the planning and scheduling of construction projects, both large and small. Whereas Gantt charts and bar chart schedules usually only depict the major items of work, properly developed and updated CPM schedules can include virtually every item of work in the contract and may contain as few as 10 or as many as 30,000 (or many more) interrelated work activities. CPM schedules have been and continue to be used as planning tools from simple to complex construction projects that require the integration of many components and incorporation of phasing and coordination. CPM schedules can be used on any size and type of construction project. If constructed properly and updated correctly, they are the most effective form of schedule for a construction project.

Most CPM schedules are updated with progress on a monthly basis, and in some instances the schedule may even be updated more frequently. When the schedule update records the project’s progress, the timing and order of the remaining work items will automatically be calculated to reflect the actual performance of the completed work items. The strength of the CPM scheduling technique is that it is a dynamic modeling tool that can identify issues and problems before they arise. If problems arise, the CPM schedule will identify potential areas of delay and provide a measure of the magnitude of the delay. The CPM schedule’s ability to accurately reflect project progress and the effect it has on the overall plan helps the project management staff to identify and deal with issues in a real-time setting. An example of a relatively simple CPM schedule is shown in Fig.

Reviews for Construction Delays

[thehacker169 · Rating: 5 out of 5 stars]

Great book to learn about construction delays. (You need schedulling background )