GE 497 Senior Design Engineering Standards. 2 Standards are detailed documents that may be rules, testing methods, definitions, recommended practices,

GE 497 Senior DesignEngineering Standards

Engineering StandardsStandards are detailed documents that may be rules, testing methods, definitions, recommended practices, or specifications that promote uniformity for engineering design, industrial practices, and terminology.Engineering standards are developed by experts within each technical field.They are usually developed in consultation with professional societies such as IEEE and ASME.There is usually ample opportunity for input by a broad constituent group of professionals and academics.

Reasons to Use Engineering StandardsStandards promote safety.The Uniform Principle of SafetyStandards promote technological development.Concurrent development of hardware and softwareStandards promote ease of interfacing.Standardized partsStandards promote uniform performance.Predictable behaviorStandards promote fairness.Standards promote professional development.

Standards OrganizationsNational Institute of Standards and Technology (NIST)Standardized weights and measurements, technological standards.Underwriters Laboratory (UL)Safety standards, especially for electrical appliancesNational Electric Code (NEC)Safety standards, especially for electrical utilities

More Standards OrganizationsAmerican National Standards Institute (ANSI) Variety of standards ranging from ASCII codes to nuts and boltsInternational Standards Organization (ISO)International standards, usually in quality (ISO-9000) and sustainability (ISO-14000)Occupational Safety and Health Administration (OSHA)Safety standards, especially in the workplace

Professional Societies and StandardsAmerican Society of Mechanical Engineers (ASME)Safety standards, especially for pressure vesselsInstitute of Electrical and Electronics Engineers (IEEE)Electronic standards, especially for computer and communication hardware and softwareSociety of Automotive Engineers (SAE)Automotive standards, especially safety and performance

Standards Promote SafetyStandards ensure both quality and specificationsGuidelines for use can become standardized into codesSafety is promoted through vast deployment

Lowers liability for companies

Standards Promote Technology DevelopmentWhen a standard is developed for a product, many competitors can design for that productThis increases choice, drives down cost, and improves qualityThis open-architecture can drive an entire market

Standards Promote Ease of InterfaceMany systems are integrated from several manufacturersStandards allow pieces to fit together, and design to be independent

Standards Lower CostA standard part gives rise to economies of scaleStandardization reduces cost through lowering of inventories and simplification of supply chains

Standards Promote Ease of MaintainenceIf parts are standardized, tools can be standardized as wellEase of inventory allows swapping of partsStandardization of parts allows a more intimate knowledge of each system.

Ethics of StandardsStandards promote safetyhold paramount the safety, health and welfare of the public Lowers Cost to Consumerserving with fidelity the public Builds on expertiseperform services only in areas of their competence

Standards exist for Ethics, too!

Corporate StandardsIn addition to industry-wide, national, and international standards, some companies have their own standards for safety and performance that may exceed required standards.It is very important to learn and follow these standards when you work for such a company.

Programming StandardsMany organizations require standard programming procedures. For example:Maximum line length of 80 characters Variables start with a lowercase letter. All word breaks should start with a capital with no delimiter between them. All variables should have names that represent their function.Class names shall start with a capital letter All functions shall be preceded with a comment listing usage of function, arguments, and return types. Comment block shall have a 60 character "***" line on top and bottom. Function names shall be verbs, and class names shall be nounsConstants shall be in all CAPS with underbars separating word breaks

Standards Are Expensive!It costs a great deal of money to develop standards.Companies and organizations recuperate that cost by selling the standards to companies and individuals, usually at a discount to their own members.Several hundred dollars is a small price to pay for a large company, but it is a lot of money to an individual.

Standards Can Be ComplicatedMost standards are hundreds of pages long, because they must fully specify the exact specifications and behavior of each element of the system described.It takes a great deal of time to thoroughly understand even one standards document.Doing so will make you very valuable to your employer!

A Short List of Electrical and Mechanical Standards for GE 497/8In this class, you must comply with the eight standards to be described in this lecture along with any other applicable standards specific to your project.All devices using 120-V AC power shall use copper wire of at least 14AWG to carry up to 20A, 12AWG to carry up to 25A, and 10AWG to carry up to 30A. (National Electrical Code Table 310.16)All devices using 120-V AC power shall be grounded and shall use a grounded plug. (National Electrical Code 250.20(B))

A Short List of Electrical and Mechanical Standards for GE 497/8All grounding connections shall be made using wire sized to match the over-current protection device of the outlet: 15A protection uses 14AWG, 20A uses 12AWG, and 30 A uses 10 AWG. (National Electrical Code Table 250.122)Standard 22 AWG hook-up wire can carry a maximum of 7A in unbundled applications and 0.92A in bundled applications. 30AWG Wire-wrap wire can carry 0.86A in unbundled applications and 0.142A in bundled applications. (Handbook of Electronic Tables and Formulas)No exposed conductors shall be at more than 14V DC above ground or above any other exposed conductors. (Underwriters laboratory standard 1446)

A Short List of Electrical and Mechanical Standards for GE 497/8All systems containing compressed gases or liquids shall comply with the ASME Boiler and Pressure Vessel Code (BPVC).All devices with exposed surfaces exceeding 140F shall be clearly marked with warning labels. (Occupational Safety and Health Administration)All lasers used in this class shall be limited to less than 5mW, and appropriate signage must be used. (ANSI standard Z136.1)

Key Take-AwaysEngineering standards promote the success of engineers in every field of study.They make peoples lives safer, more productive, and more efficient.You will need to follow corporate, industry, national, and international standards in your career.In this class, you need to follow the eight standards in this lecture as well as any other standards directly applicable to your project.