I find SIPOC diagrams really useful in the early stages of a project. They are a great way to capture a lot of information in a concise way and provide an “at a glance” view of the scope, the stakeholders and the overall process. The SIPOCs main goal as an analysis tool is drive out stakeholders and inputs & outputs, this is used alongside other tools. E.g. interviews, document analysis, etc. Once complete the SIPOC also can be used to provide an overview and context to other members of project team and stakeholders.
When putting the diagram together be careful not to confuse suppliers with Inputs or confuse customers with outputs
Suppliers – The providers of the inputs to the process, This can be people (e.g. clients, other departments, business partners) or a computer systems, or a named process etc
Inputs – These are the various inputs that are essential for the processes. These can be materials (e.g. bricks, paper, sub assemblies), resources (people, finance) and or data (e.g. a purchase order, a report, a letter, an email)
Process – The process flow should only contain 4 or 5 steps and should be kept at a high level – Detailed process flows can be created from this high level flow later
Outputs – These are ALL the products, or services that are created by the process. These can include waste outputs created by the process as well as the good stuff.
Customers – These are intended beneficiaries of the product or service, this can be the next team or process downstream, or a parallel process that depends or is impacted.
I attach a template to get you started – SIPOC Template (365)