Solid Modeling: B-rep and CSG

High-Efficiency Particulate Air (HEPA) and Ultra-Low Particulate Air (ULPA) filters are critical cleanroom components. A HEPA filter must remove at least 99.97% of airborne particles 0.3 micrometers (µm) in diameter. An ULPA filter is even more efficient, removing 99.999% of particles 0.12 µm or larger. They work via a combination of interception, impaction, and diffusion.

The PDCA cycle, also known as the Deming Cycle or Shewhart Cycle, is an iterative four-step management method used for the control and continuous improvement of processes and products. It provides a simple and effective approach for solving problems and managing change, ensuring that ideas are tested on a small scale before being implemented organization-wide.

The use of computer systems to assist in the creation, modification, analysis, or optimization of a design. CAD software allows product designers and engineers to create precise 2D and 3D models, replacing manual drafting. This technology dramatically increases productivity, improves the quality of design, and facilitates better communication through detailed visualizations and simulations.

Total Quality Management (TQM) is a management philosophy where all members of an organization participate in improving processes, products, services, and the culture in which they work. It aims for long-term success through customer satisfaction. TQM integrates quality-discipline into the culture and activities of a company, moving beyond simple product inspection to a holistic, organization-wide approach.

Concurrent engineering, also known as simultaneous engineering, is a design philosophy that emphasizes the parallelization of tasks. Instead of a sequential process where design is completed before manufacturing is considered, it involves a team-based approach where designers, manufacturing engineers, and other stakeholders work together from the outset. This overlap significantly reduces product development time and improves design quality.

Life-Cycle Assessment (LCA) is a systematic methodology for evaluating the environmental impacts associated with all stages of a product's life. This "cradle-to-grave" or "cradle-to-cradle" analysis considers raw material extraction, processing, manufacturing, distribution, use, repair, maintenance, and final disposal or recycling. It quantifies inputs like energy and raw materials and outputs like emissions to air, water, and soil.

The three pillars of sustainability, also known as the triple bottom line, is a framework that posits true sustainability requires balancing three main dimensions: environmental, social, and economic. Environmental sustainability focuses on preserving natural resources and ecosystems. Social sustainability addresses equity, community well-being, and human rights. Economic sustainability ensures long-term financial viability without compromising the other two pillars.

FMEA is a systematic, bottom-up, inductive method for identifying potential failure modes in a system, product, or process. For each failure mode, it assesses the potential effects or consequences, their severity, likelihood of occurrence, and the ability to detect them. The goal is to prioritize and mitigate high-risk failure modes before they occur.

FTA is a top-down, deductive failure analysis technique. It starts with a potential undesired event (the "top event") and uses Boolean logic gates (AND, OR, etc.) to determine the combinations of component failures or human errors that could cause it. It provides a graphical model for understanding and quantifying system risk, identifying critical failure paths.

Passive solar design is a building design strategy that uses a building's components—walls, floors, windows, and orientation—to collect, store, reflect, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. Unlike active solar heating systems, it does not involve the use of mechanical and electrical devices.

A design methodology where 'X' represents a specific product life cycle objective. DFX encompasses a collection of guidelines and techniques aimed at optimizing a product's design for a particular goal, such as manufacturability (DFM), assembly (DFA), reliability (DFR), or sustainability (DfS). This proactive approach addresses potential issues early in the design phase, reducing costs and improving quality.

To address the inability of different CAD systems to share data, neutral file formats were created. The Initial Graphics Exchange Specification (IGES), developed in the late 1970s, was an early attempt. It was later superseded by the more robust and comprehensive STEP (Standard for the Exchange of Product model data, ISO 10303), which can represent full 3D models, assembly structure, and metadata.

Parametric modeling is a CAD paradigm where designs are defined by parameters and constraints rather than just geometric shapes. Dimensions and relationships between features (e.g., parallelism, tangency) are stored as parameters. Modifying a parameter value automatically updates the entire model, maintaining the defined constraints. This approach facilitates design iteration, automation, and the creation of design families.

LCA system boundaries define which life cycle stages are included in the assessment. A "cradle-to-grave" analysis covers the entire product life, from raw material extraction through manufacturing, use, and final disposal. In contrast, a "cradle-to-gate" assessment is a partial LCA that ends when the product leaves the factory gate, excluding the use and disposal phases.