Activities: The Locus Model’s Activity Cycle

Systems Economics Lexicon · Activities & Resources: The Grammar

Every Economic System, regardless of what it actually produces, performs the same underlying sequence to produce it: procure the materials it needs, use them to produce its product, exchange that product for compensation, and manage the resources and decisions that follow. These four root activities constitute the Activity Cycle — the full ordered sequence of actions a system performs in producing a product.

Two sequences, four phases, thirty-six activities

At its most basic level, the Activity Cycle splits into two complementary halves. The Product Sequence covers Phases 1 and 2 — acquiring resources and producing the product. The Money Sequence covers Phases 3 and 4 — the product exchanged for compensation, and management decisions about how to reinvest that compensation to restart the cycle. The two sequences interact cyclically: an Economic System exchanges its finished product for money, then reinvests that money to procure the next round of materials — which is why it’s a cycle, not a one-off sequence of steps.

Each of the four phases subdivides further, using the same pre-/central-/post- logic applied twice: first into a 12-part cycle, then into the 36-part cycle the Locus language actually uses for classification. The central division of any phase is its key action — for procurement, that’s the physical transport of materials into possession; for production, that’s the act of production itself. The pre-division plans for the central action; the post-division records that it happened and checks its quality. This is also where the Locus notation comes from: an activity in the 36-part cycle is written as three digits separated by periods — phase, division, activity — the same logic as the Dewey Decimal System, just applied to economic function instead of library subjects.

Four natural relationships

Because the Activity Cycle is built by repeatedly subdividing the same two root sequences, that construction leaves behind four observable relationships between activities: the Subdivision Relationship (activities from a common division resemble each other), the Modifier Relationship (the pre-/central-/post- position implies shared characteristics regardless of phase), the Complementary Relationship (activities diametrically opposite each other share properties from their matched position), and the Order Relationship (activities near each other share properties from sequential flow). None of these are imposed on the model from outside — they fall directly out of how the 36 activities are actually constructed.

Internal vs. standardized: two ways to read the same cycle

The Activity Cycle gets used two different ways depending on the question being asked. The Reoriented Activity Cycle describes a firm’s own internal operations, with its central activity fixed at 2.2.2 regardless of what that activity actually is — an architecture firm’s central activity is designing real estate, whatever that firm’s product happens to be. The Standardized Activity Cycle instead fixes each verb’s definition against a single reference point — what a generic manufacturing company would be doing — so that classifications are comparable across the whole economy rather than internally consistent only within one firm.

Both terms have a place, at different levels of granularity: Phase 3 itself is named “Exchange” — the abstract, frame-level name for the phase. “Sell” is the specific 3.1 activity verb nested inside Phase 3, matching Chapter 3’s own reference table (“3.1: Sells the product”). The phase is Exchange; selling is one of the things that happens within it.

See also: Product Sequence · The Four Activity Cycle Relationships · Reoriented Activity Cycle vs. Standardized Activity Cycle

Part of Activities & Resources: The Grammar, course 2 of 7 in the Locus Theory series. For the full term-by-term specification, see the Lexicon.