NeSSI™is a non-affiliated international ad hoc group composed of over 250 people (and growing) including end-users such as ExxonMobil, Chevron, Dow Chemical, and Eastman Chemical, as well as manufacturers of NeSSI™ components such as ABB Analytical, Siemens, Fisher-Rosemount, Swagelok, Parker-Hannifin, CIRCOR and many others who are looking to modularize and miniaturize process analyzer sample system components. NeSSI™ operates under the sponsorship and umbrella of CPAC (Center for Process Analytical Chemistry) at the University of Washington in Seattle.

NeSSI™'s origins can be traced to various CPAC Focus Group sessions and a Tutorial presented at the November 1999 CPAC Sponsor Meeting. The membership focus of NeSSI™ has been on manufacturers who are willing to supply parts and components for this initiative as well as end-users who are willing to do "in house" testing. There are now several NeSSI™ sampling manifold designs which conform (approximately) to the SEMI 1.5" manifold. An ISA SP76 standard has been adopted.