The infrastructure industry has historically struggled to assure deadlines and costs under budget in its projects. You can find extensive bibliography on how construction has maintained its productivity rates at the same level over the last decades, while manufacturing and the economy in general have experienced exponential growth in their project execution performances.
These cost and scheduling deviations often originate during the project planning stage. Moreover, several other problems related to quality, safety, environmental and the relationship between owners and contractors are also caused by planning failures.
Emergency purchases to mitigate constraints which were not dealt with on time, low labor productivity, design inconsistencies and unmet contractual milestones are some of the problems faced by construction management teams.
Among the methodologies that have matured in the industry in recent years, aiming to tackle these problems, two have stood out: Last Planner® System and Advanced Work Packaging. For both, the Construction Industry Institute (CII) has experienced an increase in use in different types and complexity of projects, such as industrial, energy, oil and gas, real estate or transportation, as well as a greater interest from both owners and contractors in applying them to their projects.
In some earlier analysis, these construction methods were framed as competing and conflicting methodologies, but they are, in fact, based on similar foundations with complementarity processes that have synergies.
The Last Planner® System
Lean is a philosophy that focuses on optimizing costs by reducing the organization's waste, always with the best interest of the client in mind. The Last Planner® System (LPS), in turn, adapts the principles of Lean philosophy to the construction industry.
These five principles guide the processes that constitute the Last Planner® System framework:
Figure 1: Lean principles
Project planning begins with the definition of the main deliverables during the Milestone Planning, whose objective is linked to Lean Principle 1: defining what is the value for that project.
Thereafter, the activities needed to successfully complete the deliverables are detailed in a few weeks or months through Pull Planning. At this stage, the focus is on mapping the value flow, defined as Principle 2, which will be pulled from the established milestones, as indicated by Principle 4.
Figure 2: : Last Planner® System overview
Moving forward, Principle 3, Create Flow, is accomplished through a thorough Lookahead Planning, aimed to identify and remove constraints before they impact the work in the field and led by the construction team with the collaboration from all the supporting crew. Free from constraints, the Weekly Planning/Task Sheet is consolidated, reflecting the tasks that the field crew must carry out.
Finally, from daily performance meetings, often called check-in/ check-out meetings or daily huddles, status of activities are updated, as well as schedule deviations, their root cause and action plan to mitigate them, and create a continuous improvement opportunity to align with Lean Principle 5.
Advanced Work Packaging
Advanced Work Packaging (AWP) was promoted by Construction Industry Institute (CII) as a Best Practice in 2015. It aligns Engineering, Procurement, Construction and Commissioning to improve overall project performance, bridging the gap between what engineers design and what the construction team needs to do the job, through the establishment of Path of Construction and the standardization of working packages across the project, with the mindset of beginning with the end in mind.
Figure 3: Breakdown of a CWA
- Construction Work Areas (CWA): multidisciplinary project areas established to support construction strategy.
- Engineering Work Packages (EWP), Construction Work Packages (CWP) and Procurement Work Packages (PWP): discipline specific packages of a CWA.
- Installation Work Packages (IWP): detailed construction packages that can be executed without interruption.
The AWP practice brings best results when implemented from the Conceptual Engineering phase, being refined throughout Basic Engineering and in the Execution phase, in an iterative process empowered by collaboration between multidisciplinary teams. Moreover, throughout this project lifecycle, a roadmap for the project, the Path of Construction, is defined and refined as new information is made available.
The project is initially broken down in Construction Work Areas (CWA), establishing the main deliverables of the project in a geographical logic, to support construction strategy. These, in turn, are further divided into disciplines (civil, electromechanical assembly, piping, electrical, among others), creating Engineering Work Packages (EWP), Construction Work Packages (CWP) and Procurement Work Packages (PWP).
The Construction packages are subsequently detailed at the installation level and called Installation Work Packages (IWP), with the collaboration from the field crew, and are set to start only when free from constraints, with all the necessary resources properly quantified and made available, as well as the task list and requirements from safety, quality and environment.
Figure 4: Work area of a project broken down in construction work packages
Test work packages (TWP) and systems and subsystems work packages (SWP) are also defined, to enable commissioning and project startup. These packages are system generated and might require different IWP and CWP to be completed in order to be executed.
Figure 5: Schematic representation on how TWP might require the completion of IWP from different CWA.
The focus will gravitate toward reaching the best outcome when using both methodologies. The illustration below shows some guiding principles from Last Planner® System and Advanced Work Packaging, demonstrating their complementary:
With both methodologies in place, it is also possible for the deliverables of one to have their results improved by the implementation of the other:
- CWPs are detailed in IWPs during the Pull Planning phase, with the collaboration from Engineering, Procurement and other supporting areas. The selected working area will have its packages properly detailed to define the planning of the tasks, focusing on deliverables over a horizon of up to three months.
- Release of an IWP free of constraints to field teams, due to a thorough lookahead/make-ready analysis. Here, the entire supporting team gathers to evaluate the next weeks of work in advance, aiming to eliminate any constraints that may impact its flow.
- Use of IWP performance indicators collected during the execution of work in the field as inputs to the project's performance meetings. The compilation of performance information carried out by the team itself at the time of the work brings agility and, its use in project performance indicators facilitates communication between the strategic, tactical and operational levels of the project.
Finally, it is clear that these are complementary methodologies and that one is improved by the implementation of the other. While AWP focuses on the breakdown of the project into smaller and manageable parts, ensuring standardization in the information flow and facilitating communication between areas, LPS brings a collaborative management system that allows problems to be identified and resolved in time, through performance indicators and well-designed forums such as Pull Planning, Lookahead and Performance Review sessions.
Please be aware that the CII (Construction Industry Institute) currently has a working group to further explore the synergies of AWP & Lean – including Last Planner® System and other methodologies such as Target Value Delivery and Choosing by Advantages – and develop a more thorough framework for a joint implementation. An initial understanding in this ongoing working group is that, although there are plenty of successful cases in the implementation of only one of the methodologies at a time, it is becoming feasible and recommended to implement both jointly for the same project.