Life Cycle Assessment (LCA) is an assessment of the potential external impacts and is often coupled with life cycle cost (LCC) estimates to support the development, operation, and sustainment of DoD weapons systems, equipment, products, and platforms. LCAs provide a comprehensive view of a system's impact, costs, and benefits, leading to more informed decision-making that supports cost efficiency and operational readiness. By analyzing all stages of a product’s life cycle, LCAs help to: highlight areas where costs may be reduced; identify potential risks related to supply chain disruptions, resource shortages, or other challenges; and better understand longevity, reliability, and performance to ensure systems remain operational and effective when needed.

LCAs can be performed during any stage of the acquisition process to help decision makers better understand the external costs associated with technology alternatives. For more detailed guidance on performing a LCA, see DENIX's guidance report that is available for download in the Guidance Documents page of this toolkit.

The methodology for LCA and LCC estimates are outlined in the DENIX guidance and are built upon existing standards. The DENIX guidance provides a description of how to meet certain requirements within the Adaptive Acquisition Framework (e.g., Analysis of Alternatives (AoA)) and may help uncover unforeseen costs during system design. The required input data for a LCA of a given product or system include physical “flow” values (e.g., masses of materials that are consumed and produced by the system under study) as well as system cost information. The outputs of a LCA include the potential external costs such as supply chain impacts of the system under investigation, while the outputs of a LCC include traditional, internal costs. The results from LCA can inform trade-offs of alternative designs, while LCC can inform cost savings for operation and sustainment (O&S). LCAs and LCCs have been conducted on multiple weapon systems and platforms such as chromium plating alternatives for weapons systems components in the Navy, additive and traditional manufacturing for aviation fuel nozzles, and alternative engine designs for T-AGS(X) Naval Oceanographic Vessel to estimate impact of design decisions during acquisitions.

LCA and LCC Steps

The figure below demonstrates five broad, iterative steps that are recommended for conducting LCA and LCC. The LCA portion is conducted in Steps 2 and 3. In these steps, the life cycle inventory (LCI) is developed for the given system, and the associated impacts are calculated in the Life Cycle Impact Assessment (LCIA). The life cycle costs are then calculated in Step 4 based on the values contained in the LCI. The following sections describe in brief the steps performed. For a comprehensive description of these steps with examples, PIs are encouraged to review the DENIX guidance.

LCA Framework

Step 1: Define the Scope

The first step in the analysis is to define clearly the objectives and scope of the study. This includes a definition of the system(s) to be studied, the required system performance, the boundaries of the system (e.g., what specific processes are included in the scope), and any system alternatives that will also be modeled if a comparison is being made. In addition, it is important to define a functional unit that will form the basis of comparison between systems. This basis of comparison includes the functions that a system provides and is the unit on which a system’s input and output values are quantified.

Step 2: Develop a Life Cycle Inventory (LCI)

The next step is to assemble an inventory that contains all the inputs and outputs associated with any processes that fall within the system boundaries defined in Step 1 of the analysis. The table below lists examples of the types of inputs and outputs that are commonly encountered.

Example components of a life cycle inventory. The amounts of these inputs and outputs can be reported in several ways, including on a mass or cost basis.

Step 3: Generate Life Cycle Impact Assessment

Once the system’s LCI has been developed, the impacts associated with each input or output contained in the inventory can be calculated using life cycle impact assessment models. These life cycle impacts include values for issue areas such as resource availability, land use, aquatic ecotoxicity, and warfighter health burdens. The Defense Input-Output (DIO) database is an example of an impact assessment model and provides impact characterization factors for various products or activities. The DIO database is available for download in the Tools page within this toolkit. A description of several available LCA data sources and software tools can also be found in the Tools page.

Step 4: Generate LCC Estimates

The various costs associated with the system are calculated in Step 4. While the LCA conducted in Steps 2 and 3 of the analysis determines the external impacts associated with the system under study, the LCC portion assesses the costs of those impacts in a monetary value. External costs (also known as externalities) represent the costs that are borne by society and other non-DoD agencies. These potential financial liabilities are estimated using external cost factors that provide a monetary value per unit of environmental impact. External cost factors can be found in the DIO database along with the impact characterization factors. In addition, the DoD’s internal costs—including direct and indirect costs—are estimated in the LCC estimate. It is also important to understand how future events could drive additional internal costs to the DoD. These costs are referred to as “contingent costs” and are also estimated during the LCC estimate.

Step 5: Synthesize Results

In this final step, the practitioner analyzes and interprets the results of the LCA and/or LCC. This can include a comparison of the trade-offs of alternative technologies (if applicable), in addition to identifying the life cycle activities that drive impacts and costs for a particular system. During this phase of the analysis the practitioner may conclude that the comparison needs further data or adjusted system boundaries, and the previous steps in the analysis are repeated to incorporate the new information.