Operations Explore
SIPOC
SIPOC is a one-page view of a process: suppliers, inputs, process, outputs, and customers.
The questionWhere does this process start and stop, what does it consume, and who depends on what it produces?
Read in reverse order it is sometimes called COPIS. Adding constraints and measures gives SIPOC+CM.
Suppliers
- Supplier
- Warehouse
Inputs
- Invoice
- Purchase order
- Goods-receipt record
Process
- Receive invoice
- Match to order and receipt
- Route exceptions
- Approve
- Post
- Schedule payment
Outputs
- Posted invoice
- Payment instruction
- Remittance advice
Customers
- Supplier
- Treasury team
- Cost-center owners
When to use it
- People in the room describe the same process with different start and end points, and the scope argument keeps coming back.
- An improvement project is starting, and you need a boundary before detailed mapping.
- A process keeps failing at a handoff, and you need to see who supplies what to whom.
- A new sponsor or team member needs a one-page view of a process they do not run.
When to avoid it
- The problem is inside one step, such as timing, rework, a decision, or a queue. SIPOC does not show these. Use a detailed process map.
- The process is already documented and everyone agrees where it starts and stops. A SIPOC would be one more artifact.
- The question is who is accountable for each task. A responsibility matrix such as RACI is the tool for that.
- The process varies so much from case to case that a single high-level flow would mislead.
Overview
SIPOC is a one-page summary of a process in five columns: suppliers, inputs, the process in a handful of steps, outputs, and customers. It supports a scoping choice made before improvement work: where the process starts and stops, who supplies it, and who receives its results, so that later mapping and measuring cover the same thing.
It leaves out time, decisions, loops, and rework, because five to seven boxes cannot hold them. That is the reason to use it early and the reason to stop once the question moves inside a step. Teams often find that the argument over start and end points, which the page forces into the open, takes longer than the drawing.
The five columns
Suppliers
Who or what provides the inputs, inside or outside the organization. Naming a supplier forces the question of who is responsible for the quality of what arrives.
Inputs
What the process needs in order to run, whether materials, information, or services. Specify them well enough that someone could check whether they are right when they arrive.
Process
The process as five to seven high-level steps, as ASQ suggests. Verbs, in order, without decision points or loops. It is a high-level description, not a flowchart.
Outputs
What the process produces, including products, services, information, and documents. Outputs that nobody uses, and outputs that are produced but not recorded, belong on the list.
Customers
Who receives the outputs and uses them. Customers can be internal. A role, such as the treasury team, is more useful than a department or the business in general.
What it is not
- A process map. It holds five to seven boxes and leaves out decisions, loops, rework, and time. The map comes after.
- A performance measure. The basic form carries no measures. The +M variant adds them, and +C adds constraints.
The steps
-
Name the process and fix its edges
Write the process name as a verb phrase and agree its first and last step with everyone in the room before filling in any column. Expect this to be the longest part. What comes out is a start point and an end point that the room accepts.
-
List five to seven high-level steps
Use verbs, in order, without decision points. If you reach twelve steps, you are drawing a flowchart. Combine steps until the list fits. What comes out is the process column.
-
List outputs, then customers
Start from what leaves the process and who receives it, as in the COPIS order. Include internal customers, and name the role that uses the output. What comes out is two columns, with a note beside any output that has no clear customer.
-
List inputs, then suppliers
For each input, name who provides it and in what form. Flag inputs that have no clear supplier or that arrive late or wrong. What comes out is two columns, with unclear suppliers marked.
-
Check it with people who run the process
Walk the page with someone who does the work every day. Ask where it does not match what happens, and where outputs fail to meet what the customer needs. Adjust, and add constraints and measures if the project needs them. What comes out is a one-page SIPOC that the people who run the process recognize.
In practice
Three people in the room used the phrase late invoices and meant three different things. Procurement said the process started when a purchase order was raised, accounts payable said it started when an invoice arrived, and the plant said it ended when the supplier was paid. The consultant drew five columns on a whiteboard and started with outputs, not with the process.
The outputs were a posted invoice, a payment instruction, and a remittance advice for the supplier. The customers were the supplier, the treasury team, and the cost-center owners. The inputs were the invoice, the purchase order, and the goods-receipt record, and the goods-receipt record came from the warehouse, which was not part of the project. The six process steps were receive the invoice, match it to the order and receipt, route exceptions, approve, post, and schedule payment. The group agreed that the process starts at invoice receipt and ends at payment scheduling, and the warehouse was added to the interview list.
What you leave with
- An agreed start and end point, written down.
- One page with all five columns and the process in five to seven steps.
- A list of inputs with no clear supplier and outputs with no clear customer.
- A shortlist of steps that need detailed mapping, with reasons.
Failure points
Starting with the process column
The team drifts into detail, and the boundary argument reappears after the page is done. Start with the edges and the outputs.
Too many steps
Fifteen steps is a flowchart, and the one-page view is lost. Each added step moves the page toward a map that nobody will read.
Customers listed as the business
The business is not a customer. Name the role that receives the output and say what it uses it for, otherwise nobody can test whether the output is right.
Outputs that stop at the product
Rework, defects, and information the process throws away are also outputs. If the list holds only the good output, the problems stay out of the picture.
Drawn without the people who run it
A sponsor's version of the process goes on the wall, and the people who run it see it as a description of an organization that does not exist.
The failures above are usually Synthesis & Story: the work was done, but it never became one clear message a client could act on.
Origin
No author of SIPOC is reliably credited. Accounts tie it to the quality movement of the 1980s and sometimes to Philip Crosby's process model, but the lineage is not well documented. It was in use in total quality management programs by the late 1980s and later became a standard tool in the define phase of Six Sigma's DMAIC method, as well as in lean and business process management work.
There is no trademark on the name. Variants exist. COPIS fills the columns in reverse order, starting from the customer. The American Society for Quality's glossary entry also describes SIPOC+CM, which adds constraints and measures.
Further reading
- SIPOC diagram (ASQ)
The American Society for Quality's glossary entry, with a procedure, the five-to-seven-step guidance, and the SIPOC+CM variant. Free to read.
- SIPOC (Wikipedia)
A short overview with the COPIS variant and a note on the tool's history. Use it for orientation.
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