Linked set of resources and processes between multiple tiers of developers that begins with the sourcing of products and services and extends through the design, development, manufacturing, processing, handling, and delivery of products and services to the acquirer.
Sources:
NIST SP 800-37 Rev. 2 from OMB Circular A-130 (2016)

  A system of organizations, people, activities, information, and resources, possibly international in scope, that provides products or services to consumers.
Sources:
CNSSI 4009-2015

  The network of retailers, distributors, transporters, storage facilities, and suppliers that participate in the sale, delivery, and production of a particular product.101
Sources:
NIST SP 800-98 under Supply Chain

  Linked set of resources and processes between and among multiple tiers of organizations, each of which is an acquirer, that begins with the sourcing of products and services and extends through their life cycle.
Sources:
NIST SP 800-53 Rev. 5
NIST SP 800-53A Rev. 5

  Linked set of resources and processes between and among multiple levels of organizations, each of which is an acquirer, that begins with the sourcing of products and services and extends through their life cycle.
Sources:
NIST SP 800-161r1 from ISO 28001:2007 - adapted