Value chain

A firm is not a single thing that makes profit. It is a chain of distinct activities, each of which adds cost and, ideally, more value than it costs.

The value chain is Michael Porter's framework for taking a business apart into the activities through which it creates and delivers value: inbound logistics, operations, outbound logistics, marketing and sales, and service, supported by procurement, technology, human resources, and firm infrastructure. Margin is what remains when the value created exceeds the total cost of performing them.

Why disaggregation matters

The point of breaking a firm into activities is that advantage almost never lives in the whole. It lives in specific links. One company wins on a brilliant operations process, another on after-sales service, another on procurement scale. Looking at the firm as an undifferentiated lump hides where the advantage actually comes from and where it leaks away.

Disaggregation also exposes activities that destroy value, ones that cost more than they add and might be redesigned, outsourced, or dropped. The chain is a diagnostic for both edges: where to invest and where to cut.

Linkages are where it gets interesting

The activities are not independent. How a firm performs one shapes the cost or effectiveness of others. Spending more on quality inspection raises cost in one link but cuts returns and service cost downstream. These linkages are a frequent source of advantage precisely because rivals analysing single activities miss them.

This is also why advantage built across a well-linked chain is hard to copy. A competitor can imitate one activity, but reproducing the coordinated system of linkages means rebuilding the whole chain, which is far harder.

From chain to system

Porter later stressed that a firm's value chain sits inside a larger value system, linking the chains of suppliers and buyers. Advantage often comes from managing those external linkages well, helping a supplier cut cost or a customer use the product more effectively.

Used well, the value chain turns a vague ambition to be more competitive into a concrete map: which activity, which linkage, which cost, which buyer benefit. It is less a theory than a discipline for locating advantage where it actually resides.