Process variability: why some processes travel badly

Key takeaways

Process variability is how much the inputs, steps or outputs of a process differ from one case to the next. Low-variability processes, where most cases follow the same path, outsource well. High-variability processes, where each case needs a fresh judgement, travel badly. Measure it by sampling 20 recent cases and counting how many followed the standard path.

• Sample 20 recent cases and count the standard ones.
• 80% or more on the standard path: low variability.
• Under 60%: reduce variation or split the process.
• Input variation is easier to fix than step variation.

What causes variation in business processes?

Three sources: inputs, steps and outputs. Input variation is when the work arrives in different forms, such as invoices by post, email and portal. Step variation is when people do the work differently. Output variation is when customers or managers want different results. Input and step variation can usually be reduced; output variation often reflects genuine choice.

• Which business processes should you outsource?
• Process standardisation: one best way, lower cost per task

How do you measure process variation?

Take 20 recent cases and trace each through the process. Mark whether it followed the standard path or needed something different, and why. If 16 or more followed the standard path, variability is low. If fewer than 12 did, the process needs work before it travels well.

• Pick 20 recent cases at random.
• Trace each from trigger to output.
• Mark standard or non-standard.
• Note the reason for each exception.

• Exception handling: the few cases that drive most cost
• Quality sampling: how many outsourced items to check

How do you reduce variability before outsourcing?

Standardise inputs first, with one intake route and a template or form. Then agree one method for the steps, and write rules for the common exceptions. The cases that remain unusual become escalations to your team. Reducing variation also cuts errors, because people make more mistakes on cases that look slightly different.

• Work request intake: one form for every routine job
• Decision tables: turn judgement calls into clear rules
• Human error in repetitive tasks: why good people slip

When is high variability a reason to keep a process?

When the variation is the value. Bespoke quotes, complex complaints and specialist advice vary because each customer's situation does. Forcing them into a standard path would harm the result. Keep these in-house, or outsource only the routine preparation around them.

• Rule-based vs judgement tasks: what to hand over
• Outsource, split, fix or keep: four process verdicts

What does this look like in practice?

A pattern we see: most of a process's variation comes from two or three input sources. Fixing the intake removes half the exceptions before any step changes.

• See client work
• BPO Solutions for UK businesses

Variability checklist

Run these checks on each candidate process.

• Sample 20 cases and count the standard path.
• List the top three causes of exceptions.
• Standardise how work arrives.
• Agree one method for the steps.
• Write rules for common exceptions.
• Decide which cases escalate to you.

• How much volume makes a process worth outsourcing?
• The process selection score: outsource, split or keep?

Next step

Sample 20 cases from your candidate process and send us the reasons for any exceptions. We will tell you which variation to remove and whether the process is ready to move.