A supply chain is the full path a product takes from raw material to the customer's hands: suppliers, manufacturing, transport, storage, and delivery, plus the returns that come back. It also covers the information and payments that move alongside the goods. Service businesses have one too, made of tools and subcontractors.
Two numbers describe most of it: lead time and minimum order quantity. Lead time is how long it takes from order to arrival. Minimum order quantity is the smallest batch a supplier accepts. A candle maker whose supplier requires 1,000 jars with a 10 week lead time must decide 10 weeks in advance and pay for 1,000 jars, even if she sells 120 per month. At 1.20 euros per jar, that is 1,200 euros tied up for about eight months of sales.
This is why supply chains belong in your cash plan, not only in the operations section. Money leaves early and comes back late. If you pay a supplier 30 days before shipping and your customers pay 30 days after delivery, you finance that gap yourself.
Founders usually underestimate three things. First, single points of failure. One supplier, one factory, or one shipping route means one problem stops everything. A second qualified supplier costs time now and saves a season later. Second, the true landed cost. The unit price is not the cost. Add freight, customs duty, insurance, handling, and returns, and the total is often 20 to 40 percent above the quoted price. Third, returns. Planning the forward flow but not the way back leaves you without a process when 8 percent of orders arrive back damaged.
Write down each step, who does it, how long it takes, and what happens if it fails. That short table is more useful than a diagram.
