Predicting the Future: Life Cycle Cost Modeling for Waterfront Facilities

Structural rehabilitation of maritime assets | Photo credit: Jacobs

It is no secret that the operation of waterfront infrastructure requires substantial investment. Undertaking work along the waterfront is challenging due to the dynamic marine environment, the need for underwater repairs by divers, limited access, the age of existing structures, often harsh environmental conditions, and the need to minimize operational disruptions. All of these factors make the maintenance of waterfront infrastructure far more difficult and costly than typical inland facilities. Identifying where and when funds will be needed is an additional challenge.

In response, Jacobs has developed life cycle cost models to help owners of large waterfront facilities prepare and plan for the maintenance of maritime assets over the long and short term. A life cycle cost model simulates the gradual deterioration of individual elements and uses this information to estimate the long-term repair costs associated with maintaining waterfront assets. When developing a life cycle cost model, it is important to consider the following stages:

Frame the Boundaries. The first step of any life cycle cost analysis is to identify the facility and the limits of what will be included or not included. This is not just the big picture, identification of the structures, such as piers and wharves, but also definition of which elements will be modeled. For example, the scope of the program may include modeling of pile repairs, which is typically a significant cost driver, but not include underdeck repairs. The analysis may be limited to structural elements or also include replacement of equipment or utilities. The team should agree to an appropriate study period, often 25-50 years, and the overall goals of the program.

Define Deterioration Mechanisms. Before setting up the model, the team identifies the structural elements’ failure mechanisms, and defines appropriate deterioration and failure rates. Typically waterfront structures consist of steel, timber, and concrete. Steel and timber follow a somewhat predictable deterioration pattern, whether corrosion driven or due to marine borer activity. However, concrete deterioration is not only driven by environmental considerations but is also sensitive to installation and construction issues. For this reason, steel and timber deterioration are often modeled with an assumed annual deterioration rate for the individual elements, whereas modeling concrete repairs typically evaluates historic performance to predict a future repair rate.

Collect input data. To build a life cycle cost model, real data is needed. This includes the physical measurements to run capacity calculations such as length and diameter, as well as information about the use of the site and anticipated load ratings.  More data might make the model more accurate, however it is also more expensive and can be harder to obtain. While some life cycle analysis efforts can fund a specific underwater inspection and obtain current data for each element at the onset of the study period, more commonly, a team may need to rely on historic inspection reports and condition ratings to draw assumptions for the current capacities of thousands of elements.

Structural inspection of maritime assets |
Photo credit: Jacobs

Run Analysis. The life cycle model should start by checking the capacity of elements in their current condition – elements which are structurally deficient are assigned a repair in that year. The model generates the required repair length (or appropriate measure). The model then advances the deterioration on the remaining, unrepaired elements and again checks the capacity. This continues year over year until all elements qualify as structurally deficient. As elements are flagged as structurally deficient, for each year of the analysis, a cost is assigned to the repair associated with that element.

Discuss and Re-calibrate. A life cycle model can be an incredibly powerful tool which will lead to new ideas and discussions surrounding maritime maintenance methodologies. With an understanding of the need and timing of structural repairs, life-cycle costs could be minimized by selecting the ideal type of repair program. The traditional life cycle cost analysis assumes structural elements would be repaired only after significant deterioration has taken place: the point when the condition has reduced the load carrying ability of the element. A second, preventative, approach proposes that structural elements are proactively repaired to extend the service life of the element by protecting it from further deterioration. Preventative maintenance repairs are typically installed on elements that can safely carry applied design loads in their existing condition and are not meant to increase load-bearing capacity or restore load paths; they are, therefore, often less costly than structural repairs. These repairs can be installed at any time in the lifecycle prior to needing a structural repair. A third strategy would be full replacement of the structure. With an accurate life cycle analysis, these three repair strategies can be analyzed and compared for a “best fit” approach to the facility needs and availability of funding over the study period

A well-planned maintenance program can be a sustainable and cost-effective solution to maintain and extend the life of our aging maritime infrastructure. Jacobs delivers comprehensive asset management and a proactive maintenance process to help our clients achieve their missions, realize value from their assets, and deliver results that meet the expectations of their stakeholders.

Find out more about Jacobs’ Ports & Maritime solutions.

Contact us at PortsAndMaritime@jacobs.com to see how we can help identify the right solutions for your challenges.

At Jacobs, we’re challenging today to reinvent tomorrow by solving the world’s most critical problems for thriving cities, resilient environments, mission-critical outcomes, operational advancement, scientific discovery and cutting-edge manufacturing, turning abstract ideas into realities that transform the world for good. With approximately $14 billion in revenue and a talent force of more than 58,000, Jacobs provides a full spectrum of professional services including consulting, technical, scientific and project delivery for the government and private sector.

Jacobs ranks as the #1 Marine and Port Facilities firm in Engineering News Record’s rankings. As one of the largest ports and maritime consultancies in the world, we have an extensive in-house global maritime group, providing our clients with unrivaled marine analysis, assessment, planning, design, development, project management, and project delivery services. We hold marine design, engineering, and construction-related services contracts with clients around the world, providing us with extensive experience within the marine, port, and waterfront industry.

Our asset management services help ensure that investment in the operation, maintenance, and improvement of marine infrastructure is directed at providing maximum benefit for end users at the lowest life cycle cost. We assist our clients in targeting spending to maintain the physical and financial value of assets, while optimizing their overall performance within the context of the client’s specific strategic business objectives.

Visit jacobs.com and connect with Jacobs on FacebookInstagramLinkedIn and Twitter.