A chain that is really a network
A supply chain is the sequence of organizations and activities that turn raw materials into a product and deliver it to a customer. The word “chain” suggests a neat line, but real supply chains are usually networks. A single product may draw on dozens of suppliers, and one supplier may serve many manufacturers. The stages below describe the typical flow, simplified for clarity.
To keep things concrete, imagine a wooden chair sold in a store. Real products differ, and some stages are skipped or combined in practice.
Stage 1: Raw materials and extraction
Everything starts with natural resources or basic inputs: timber, metals, crops, oil, minerals. These are grown, harvested, mined or otherwise obtained. For the chair, this is the forestry operation that supplies wood, plus the sources of metal for fasteners and the materials for finishes.
Things that matter at this stage include seasonal availability, weather, regulations on land and resource use, and the distance to the next stage. Raw materials are often heavy and bulky, so they tend to travel by modes suited to large volumes, such as bulk cargo by sea or rail.
Stage 2: Processing and component manufacturing
Raw materials are rarely used as they are. A sawmill cuts and dries timber; a mill turns metal into screws; a chemical plant makes varnish. Outputs of this stage are components and intermediate materials.
This stage often involves several tiers of suppliers. A chair maker might buy from a wood supplier, which in turn buys from sawmills, which buy from forest owners. A business usually knows its direct suppliers well but may know much less about the ones behind them, which is the problem addressed by supply chain mapping.
Stage 3: Assembly and final manufacturing
Components come together to form the finished product. The chair factory cuts, joins, sands, finishes and packs chairs. Production planning decides what to build and when, balancing expected demand against machine and labor capacity.
Here the manufacturer faces choices about how much stock of parts to hold. Approaches such as just-in-time aim to receive parts close to when they are used, while others keep larger buffers. Some companies hire outside factories for production, a pattern discussed under contract manufacturing.
Stage 4: Packaging and storage
Finished products are packaged to survive transport and handling, labeled for identification, and stored until they are shipped. For the chair, that means flat-pack boxes or protective wrapping, labels that identify the product and a place in a warehouse. Good shipping packaging reduces damage but also affects how efficiently trucks and containers are filled.
Stage 5: Distribution
Distribution moves finished goods from the factory toward customers. It commonly includes:
- Transport from the factory by truck, rail, ship or air, chosen according to speed, cost and reliability.
- Warehouses or distribution centers that receive, store and sort goods for onward delivery.
- Regional hubs that break large shipments into smaller ones heading to local areas.
If the chair is made abroad, this stage includes ocean shipping, border formalities such as customs clearance, and onward transport inland. This stage is where most of what people call logistics takes place, although logistics also operates in the earlier stages.
Stage 6: Retail or sale
Products reach the point where customers can buy them: a store, a website, a wholesaler or a direct sales channel. Stores need goods on shelves in the right quantities. Online sellers need stock ready for picking and packing.
At this stage, the supply chain meets demand most directly. Retailers see what actually sells, and that information is valuable to everyone upstream. If it travels poorly, upstream firms may over- or under-produce. A related pattern is the bullwhip effect, in which order swings grow larger as they move back toward the raw material end.
Stage 7: Delivery to the customer
For goods bought in a store, the customer takes the product home, so this stage is the customer’s own journey. For goods bought online, it is the delivery to the customer’s address. The last leg is known as last-mile delivery, and it is often relatively expensive per item because it involves many individual stops.
Increasingly, customers can choose alternatives such as collecting from a convenient site, as covered under pickup points.
Stage 8: Use, returns and end of life
The chain does not necessarily end at the sale. Customers may return products, repair them, resell them or eventually dispose of them. Handling these flows is called reverse logistics. Some businesses try to recover value by refurbishing, recycling or reusing materials. Ideas such as circular supply chains aim to make this loop a regular part of the design rather than an afterthought.
Information and money flow too
Alongside the physical movement of goods, two other flows run through the chain.
- Information moves in both directions: orders and forecasts flow back toward suppliers, while shipping notices and status updates flow forward. The degree to which partners can see this information is covered under supply chain visibility.
- Money moves mostly in the opposite direction to goods: customers pay retailers, who pay distributors, who pay manufacturers and so on. Payment arrangements affect how much cash is tied up at each stage.
Where things commonly go wrong
Problems can arise at any stage, and their effects often spread.
- A crop failure or mine closure at the start can limit what everything downstream can make.
- A single-source supplier outage can halt a factory.
- A port delay or congestion slows distribution.
- Inaccurate demand forecasts lead to stockouts or excess inventory.
- Poor communication means one stage cannot react to changes in another.
Because of these dependencies, companies increasingly look at risks across the entire network rather than just their nearest partners, and ideas like supply chain resilience have grown in prominence.
A note on variation
Not every product follows all eight stages. Fresh food may skip most manufacturing, digital goods bypass physical distribution, and a service business has a different structure altogether. The stage model is a way of organizing thought, not a rigid template. For a view of how the physical work in these stages differs from the wider coordination around them, compare logistics with supply chain management.