多年来，用于指定和购买测量设备的流程不断发展。设备采购经历了几个不同的阶段:1）根据客户蓝图规范进行采购:2）通过电子表格分析来评估供应商的能力:以及3）客户和供应商之间的交互过程来设计系统。然而，在这些步骤之前，项目中一个经常被忽视的方面是对导致购买机器的内部因素的深入分析。本文强调了流程的两个部分以及它们之间的相互作用，并提出了供应商选择的方法。

THE PROCESS USED TO SPECIFY AND PURCHASE MEASURING EQUIPMENT HAS EVOLVED THROUGH THE YEARS. EQUIPMENT PURCHASE HAS GONE THROUGH SEVERAL DISTINCT STAGES: 1) PURCHASE TO CUSTOMER BLUEPRINT SPECIFICATION: 2) SPREADSHEET ANALYSIS TO EVALUATE SUPPLIER'S CAPABILITIES: AND 3) AN INTERACTIVE PROCESS BETWEEN THE CUSTOMER AND THE SUPPLIER TO THE DESIGN SYSTEM. BEFORE THESE STEPS, HOWEVER, AN OFTEN OVERLOOKED ASPECT OF THE PROJECT IS AN IN-DEPTH ANALYSIS OF THE INTERNAL FACTORS LEADING TO THE PURCHASE OF THE MACHINE. THIS PAPER HIGHLIGHTS BOTH SEGMENTS OF THE PROCESS AND THE INTERACTION BETWEEN THEM, AND PROPOSES A METHODOLOGY FOR VENDOR SELECTION.