Life-cycle engineering (LCE) is a sustainability-oriented engineering methodology that takes into account the comprehensive technical, environmental, and economic impacts of decisions within the product life cycle. Alternatively, it can be defined as "sustainability-oriented product development activities within the scope of one to several product life cycles."[1] LCE requires analysis to quantify sustainability, setting appropriate targets for environmental impact. The application of complementary methodologies and technologies enables engineers to apply LCE to fulfill environmental objectives.
LCE was first introduced in the 1980s as a bottom-up engineering approach, and widely adopted in the 1990s as a systematic 'cradle-to-grave' approach.[2] The goal of LCE is to find the best possible compromise in product engineering[3] to meet the needs of society while minimizing environmental impacts.[4] The methodology is closely related to, and overlaps with, life-cycle assessment (LCA) to assess environmental impacts; and life cycle costing (LCC) to assess economic impacts.The product life cycle is formally defined by ISO 14040 as the "consecutive and interlinked stages of a product system, from raw material acquisition or generation from natural resources to final disposal."[5] Comprehensive life cycle analysis considers both upstream and downstream processes.[6] Upstream processes include "the extraction and production of raw materials and manufacturing," and downstream processes include product disposal (such as recycling or sending waste to landfill). LCE aims to reduce the negative consequences of consumption and production, and ensure a good quality standard of living for future generations, by reducing waste and making product development and engineering processes more efficient and sustainable.
Life cycle engineering is defined in the CIRP Encyclopedia of Production Engineering as:
"the engineering activities which include the application of technological and scientific principles to manufacturing products with the goal of protecting the environment, conserving resources, encouraging economic progress, keeping in mind social concerns, and the need for sustainability, while optimizing the product life cycle and minimizing pollution and waste."
The definition of LCE is often challenged in regard to its primary purpose, but the consensus purpose of LCE is to evaluate and contribute to the improvement of environmental, health, and overall sustainability services and consequences of products at all life cycle stages.[7]
The first step in completing LCA or LCE is determining the appropriate sustainability thresholds to use as environmental targets for the product system. The proposed Lyngby framework for LCE is a combined top-down and bottom-up approach for LCE that uses targets based on planetary boundaries. Planetary boundaries can be used to establish limits for the earth's carrying capacity, defining upper thresholds for the environmental system.[8]
The IPAT equation [Impact = Population (or Volume) x Affluence (or Consumption) x Technology (or Consumption per Unit Produced)] is an accepted method for quantifying the impact of consumption. LCE can be leveraged to manage total environmental impact by addressing the technology effect (single product and product life cycle) and the volume effect (anticipated volume growth as consumption and population increase) of product engineering. Impacts are considered within the context of technical boundary conditions to verify the feasibility of proposed solutions.
Modern technology provides innovative new opportunities for LCE:
LCE is most commonly used as a part of green building rating systems or individual parties aiming to assess environmental or sustainability consequences of specific building projects or products. Stakeholders that want to develop more sustainable operations on a life-cycle level or assess their products from a life-cycle perspective use LCE to assess and improve operations to maximize efficiency and meet desired environmental or economic goals. Minimizing adverse environmental consequences and optimizing resource use are two central concepts to the application of LCE.
A major implementation of LCE on an international scale is in the United Nations' Sustainable Development Goals (SDG). The SDGs are 17 goals for international environmental, economic, and social complications or subjects that are to be addressed by 2030. LCE is to be implemented in the solutions to these issues, as they require evaluation and action on a full life-cycle level, and are directly or indirectly tied to sustainable policies and decision-making.
Key themes in LCE are economic, social, environmental and technological. These themes are interlinking and can be influenced by life cycle engineering.
| Economic | Economic costsProfitability
Quality of products Impact on future investments | |
| Social | DemographicsFuture generations Backing from environmentalists | |
| Technological | ManufacturingEfficiency | |
| Environmental | Eco-designWaste reduction |
Life cycle engineering is an assessment methodology and practice faced with increasing demand in the architectural, construction, and design industries. The shift toward "green building" or sustainable construction has increased the need for LCE in the design, construction, operation, and demolition of buildings. Newly realized environmental and economic benefits of sustainable building practices are determined and made accessible through LCE. LCE provides value to businesses by revealing and quantifying the benefits of sustainable construction with regard to environmental impact, energy reduction, economic savings, and commercial or social attractiveness. The costs LCE or of conducting life-cycle assessment (LCA) and life-cycle cost analysis (LCCA) are outweighed and justified by the benefits of such assessments, increasing the integration of LCE within sustainable construction practices.
Specific demand for LCE in sustainable construction practices can be attributed to green building rating systems such as Leadership in Energy and Environmental Design (LEED) – developed by the U.S. Green Building Council – and Green Globes – developed by the Green Building Initiative. Green building rating systems have supported and encouraged the use of LCE and LCA as methods to improve the standards and requirements of rating systems, while also advancing industry-wide standards for integrated building sustainability considerations.[13]
Concluding paragraph of an earlier article on life cycle assessment (ref : Life-cycle assessment)Life Cycle Engineering of Material in Service "plays a significant role in saving energy,[1] conserving resources [2] and saving billions by preventing premature[2] failure of critical engineered component in a machine or equipment. LCA data of surface engineered materials[3] are used to improve life cycle of the engineered component.. Life cycle improvement of industrial machineries and equipment including, manufacturing, power generation, transportations, etc. leads to improvement in energy efficiency, sustainability and negating global temperature rise.[1] [4] Estimated reduction in anthropogenic carbon emission is minimum 10% of the global emission.[1] "1 R.Chattopadhyay: Green Tribology, Green Surface Engineering and Global Warming,2014, ASM International, OH, USA 2. R.Chattopadhyay: Surface Wear, Analysis, Treatment, and Prevention, 2001, ASM International, OH, USA 3. R.Chattopadhyay: Advanced Thermally Assisted Surface Engineering Processes, 2004, Springer, NY, USA. 4. R. Chattopadhyay and Mandira Chatterjee: Global Warming: Origin, Significance, and Management, 2012, Global Vision Publishing, New Delhi, India.