Business and Technology · Competitive factors

Porter's Value Chain: Primary and Support Activities

Updated 11 October 2026 · Fact-checked

Porter's value chain splits a business into the activities that create value for customers. Five primary activities (inbound logistics, operations, outbound logistics, marketing and sales, service) are supported by four support activities (procurement, technology development, human resource management, firm infrastructure). You analyse each to find cost savings or ways to differentiate.

Understand Porter's Value Chain

A business does not earn profit from the whole organisation at once. It earns profit from a series of separate activities. Michael Porter's value chain lists these activities so you can see where value is created and where cost is incurred.

The idea is simple. Customers pay a price. The business spends money carrying out its activities. If the price is higher than the total cost of the activities, the business earns a margin. The value chain helps you ask: which activities add the most value, and which cost too much?

Porter splits activities into two groups. Primary activities are directly involved in making and selling the product and serving the customer. Support activities help the primary activities work and run across the whole business.

The value chain links to competitive advantage. A firm can gain cost advantage by performing activities more cheaply than rivals, or by redesigning them. It can gain differentiation by performing activities in a way that customers value and will pay more for. Either route can lead to a higher margin.

The business sits inside a wider value system. This includes the value chains of suppliers, distributors and customers. The value chain looks inside one organisation. The value system looks at the whole flow, from raw materials to the final buyer. Cost and value can be gained or lost in the links between chains, not only inside your own.

Key formulas to remember

Primary activities (5): Inbound logistics → Operations → Outbound logistics → Marketing and sales → Service; These follow the flow of the product to the customer. Remember the order.
Support activities (4): Procurement; Technology development; Human resource management; Firm infrastructure; They support all primary activities. Procurement means buying inputs, not the inbound logistics of receiving them.
Margin: Margin = Value to customer (price paid) − Total cost of value activities; Porter shows margin as the end of the chain. Improve it by cutting cost or raising value.
Value chain versus value system: Value chain = one organisation's activities; Value system = chains of suppliers, the firm, distributors and customers; Use value system when a question mentions linkages outside the firm.

How to solve Porter's Value Chain questions

Use this method for any BT question on the value chain, whether it is a definition, a classification or a scenario.

1Read the question and decide what is asked: classify an activity, explain a term, or suggest how to gain advantage.
2Identify the organisation's product and how it reaches the customer. This sets the primary activities.
3Match each activity in the scenario to one of the five primary or four support activities. Ask: is it directly making, delivering or selling, or does it support the whole business?
4Check for tricky pairs: procurement (buying) against inbound logistics (receiving and storing), and technology development (any know-how, not only IT) against operations.
5Decide the goal: cost advantage (do the activity cheaper or more efficiently) or differentiation (do it in a way customers value more).
6Look for linkages between activities, such as better design lowering service costs, or links to suppliers and customers in the value system.
7Give a clear answer using the exact terms. In multiple response questions, select exactly the number asked.

Quickest way: Three-question activity sort

When to use it: Use this in Section A when you must classify an activity quickly as primary or support, and name which one.

Ask: does it touch the physical product or customer directly? If yes, it is primary.
Primary order test: goods in = inbound; making = operations; goods out = outbound; promoting and selling = marketing and sales; after-sale help = service.
If it serves the whole business (buying, recruiting, R&D, systems, finance, legal, planning), it is support. Buying is procurement, people is HRM, R&D and systems is technology, finance and management is firm infrastructure.

Common mistakes in Porter's Value Chain

Treating procurement as inbound logistics.
Both deal with inputs, so they sound the same.
Fix: Procurement is the act of buying and negotiating with suppliers. Inbound logistics is receiving, storing and handling those inputs. Procurement is a support activity; inbound logistics is primary.
Thinking technology development means only IT.
The word technology suggests computers.
Fix: It covers all know-how used in the business, including product design, R&D and process improvement. Software systems can also sit here.
Calling after-sales support a support activity.
The word support appears in both the activity and the group name.
Fix: After-sales help is the primary activity called service. Support activities are the four that run across the whole firm.
Confusing the value chain with the value system.
Both use chain language and both show how value flows.
Fix: The value chain is inside one firm. The value system adds suppliers, distributors and customers. Pick the term that matches the scope in the question.
Listing activities without linking them to advantage.
Students memorise the lists and stop there.
Fix: Always say how an activity can lower cost or differentiate the product. That is the purpose of the analysis.
Putting firm infrastructure as only buildings.
Infrastructure sounds physical.
Fix: Here it means general management, planning, finance, legal and quality management that support the whole business.

Worked examples

Example 1

A clothing company designs garments in-house, buys cotton from suppliers, stores fabric in its warehouse, sews garments in its factory, delivers to shops, advertises online and offers a repair service. Classify each activity under Porter's value chain: (a) buying cotton, (b) storing fabric, (c) sewing, (d) repair service, (e) designing garments.

Show the solution

(a) Buying cotton is the act of purchasing inputs. This is procurement, a support activity.
(b) Storing fabric is receiving and holding inputs. This is inbound logistics, a primary activity.
(c) Sewing turns inputs into the finished product. This is operations, a primary activity.
(d) A repair service is help given after the sale. This is service, a primary activity.
(e) Designing garments is product design and know-how. This is technology development, a support activity.

Answer: (a) Procurement (support); (b) Inbound logistics (primary); (c) Operations (primary); (d) Service (primary); (e) Technology development (support).

Example 2

A budget airline wants a cost advantage over rivals. Explain, using the value chain, two ways it could achieve this and name the activity involved in each.

Show the solution

Identify the goal: cost advantage means doing activities more cheaply than rivals.
First way: sell tickets directly through its own website and app instead of travel agents. This reduces cost in marketing and sales, a primary activity.
Second way: negotiate bulk fuel and aircraft purchase deals with suppliers. This reduces cost in procurement, a support activity.
Link to margin: lower activity costs with the same ticket price give a higher margin, or allow lower prices to win customers.

Answer: Direct online selling lowers costs in marketing and sales (primary). Bulk purchasing lowers costs in procurement (support). Both cut total activity cost and so improve margin or allow lower prices.

Exam tips

Learn the five primary activities in order and the four support activities as a list. Section A questions often ask you to classify one activity.
Watch the procurement versus inbound logistics trap. Check whether the item is buying or receiving and storing.
For multiple response questions, read how many options to select and pick exactly that number.
In Section B scenarios, always tie an activity to cost advantage or differentiation. A bare list earns little.
If a question mentions suppliers, distributors or customers, think value system and linkages, not just one firm's chain.

Practice questions from Competitive factors

Porter's Value Chain in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Porter's Value Chain: frequently asked questions

What are the primary and support activities in Porter's value chain?

Primary activities are inbound logistics, operations, outbound logistics, marketing and sales, and service. Support activities are procurement, technology development, human resource management and firm infrastructure. Primary activities create and deliver the product; support activities help them across the whole business.

What is the difference between a value chain and a value system?

The value chain covers the activities inside one organisation. The value system includes the value chains of suppliers, distributors and customers too. It shows how value is created along the whole path from raw materials to the final buyer.

How do I draw the value chain in the ACCA BT exam?

BT is a computer-based exam with objective questions, so you rarely draw it. You need to know the layout: support activities across the top and primary activities below, ending in margin. In practice you mainly classify activities and explain how they give advantage.

How does the value chain help find cost advantage and differentiation?

By analysing each activity you can see where cost is high or where customers value quality. You can then cut cost in an activity, or improve it so customers pay more. Linkages between activities can also reveal savings.