Method

SIPOC

In French: SIPOC

A SIPOC describes a process on one page in five columns — suppliers, inputs, process, outputs, customers — to agree on its scope before analysing it.

What it is

SIPOC is the acronym of Suppliers, Inputs, Process, Outputs, Customers. It is the typical deliverable of the Define phase of a DMAIC project, and its goal is not to describe the process in fine detail but to delimit what is being talked about.

The central column must hold only four to seven high-level steps. A SIPOC that spills over two pages has missed its function: it is no longer a framing, it is a map — and the map will come later, once the scope has been accepted by everyone.

One reflex that greatly improves the result: fill it in from right to left. You start with the customer and what they receive, then work back. Filled in reading order, the SIPOC describes what the organisation does; filled in backwards, it describes what it produces for someone.

What it then makes possible

Once the customers are identified, their voice (VOC) can be collected and translated into measurable characteristics — the CTQs, critical to quality. That is the necessary step between "customers complain about lead times" and "processing time must be under five days in 95 % of cases".

The Inputs and Outputs columns also serve to spot where to measure. An uncontrolled input is a source of variation, and it is often there that the Measure phase finds its first data.

SIPOC, flowchart or VSM?

All three describe a process and answer different questions. The SIPOC frames: what is being talked about, where it starts, who receives the result. It fits on one page and is read in a minute.

The flowchart details the actual sequence of operations, with its decisions, its loops back and its special cases. It is the one that brings out the rework and the approvals that the SIPOC aggregates into a single step.

Value stream mapping adds time and stocks, and separates the physical flow from the information flow. It is the only one of the three that shows how long nothing happens.

The usual order is that one, and it is not indifferent: frame, then detail, then measure. Starting with the VSM of a scope whose boundaries nobody has defined amounts to precisely measuring something that has not yet been decided.

The common mistake

Doing it alone, at your desk, because it is quick. A SIPOC has little documentary value; all its value lies in the discussion it provokes. It is by building it together that you discover that two departments do not have the same idea of where the process starts — and that discovery is worth more than the document.

On the shop floor — Financial services

On an account-opening process, the SIPOC brought out that sales and the back office did not count the lead time from the same event: the signature for one, receipt of the complete file for the other. Three days apart, and two years of disagreement over the figures.

The other tools illustrated by this trade: banking, insurance and back office.

An article that covers it

Combien de temps faut-il pour préparer une Green Belt ?

Frequently asked questions

What does the acronym SIPOC mean?

Each letter names a column of the table: S for the suppliers, I for what they bring, P for the main transformation phases, O for what comes out, C for those who receive it. Each column is filled with named items — a specific supplier, a specific document — and not with general categories.

At what point in a project is a SIPOC done?

At the very beginning, during framing, before the slightest data collection. It serves to obtain explicit agreement on where the process starts, where it stops, and the identity of those who receive its result. Building it after having measured amounts to documenting a scope that had been chosen without saying so.

How many steps should go in the central column?

Four to seven, and that constraint is part of the tool rather than a limitation of it. It forces reasoning in main phases instead of listing operations. When the list grows longer, it is the sign that one has slipped towards a more detailed deliverable, whose turn will come later in the project.