ISO 14253-2:2011指导实施“测量不确定度估算指南”（简称GUM）的概念，用于工业中用于校准（测量）标准和现场测量设备的GPS和工件GPS特性的测量。目的是提供有关如何实现不确定性陈述的全面信息，并为测量结果及其不确定性（买方与供应商之间的关系）进行国际比较提供依据。 ISO 14253-2:2011旨在支持ISO 14253-1。这两个部分都有利于公司解释GPS规格的所有技术功能[即工件特性公差和测量设备计量特性的最大允许误差值（MPEs）]。 ISO 14253-2:2011引入了不确定性管理程序（PUMA），这是一个基于GUM的实用的迭代过程，用于估计测量的不确定度，而不改变GUM的基本概念。通常用于估计测量的不确定性并给出以下不确定性的陈述:单次测量结果;比较两个或多个测量结果;比较o

ISO 14253-2:2011 gives guidance on the implementation of the concept of the "Guide to the estimation of uncertainty in measurement" (in short GUM) to be applied in industry for the calibration of (measurement) standards and measuring equipment in the field of GPS and the measurement of workpiece GPS characteristics. The aim is to promote full information on how to achieve uncertainty statements and provide the basis for international comparison of measurement results and their uncertainties (relationship between purchaser and supplier). ISO 14253-2:2011 is intended to support ISO 14253-1. Both parts are beneficial to all technical functions in a company in the interpretation of GPS specifications [i.e. tolerances of workpiece characteristics and values of maximum permissible errors (MPEs) for metrological characteristics of measuring equipment]. ISO 14253-2:2011 introduces the Procedure for Uncertainty MAnagement (PUMA), which is a practical, iterative procedure based on the GUM for estimating uncertainty of measurement without changing the basic concepts of the GUM. It is intended to be used generally for estimating uncertainty of measurement and giving statements of uncertainty for: single measurement results; the comparison of two or more measurement results; the comparison of measurement results from one or more workpieces or pieces of measurement equipment with given specifications [i.e. maximum permissible errors (MPEs) for a metrological characteristic of a measurement instrument or measurement standard, and tolerance limits for a workpiece characteristic, etc.], for proving conformance or non-conformance with the specification. The iterative method is based basically on an upper bound strategy, i.e. overestimation of the uncertainty at all levels, but the iterations control the amount of overestimation. Intentional overestimation and not underestimation, is necessary to prevent wrong decisions based on measurement results. The amount of overestimation is controlled by economical evaluation of the situation. The iterative method is a tool to maximize profit and minimize cost in the metrological activities of a company. The iterative method/procedure is economically self-adjusting and is also a tool to change/reduce existing uncertainty in measurement with the aim of reducing cost in metrology (manufacture). The iterative method makes it possible to compromise between risk, effort and cost in uncertainty estimation and budgeting.