Six Sigma in the IT and Software Fields

Six Sigma is usually seen as applicable to manufacturing, but not to the IT and software fields. Can Six Sigma relate to this industry rather than manufacturing? Is there any value in doing so?

This article will introduce the Six Sigma concept of measuring defects, then relate this to several potentially valuable metrics for IT and software.

In this article, “IT” generally means delivering IT services, such as computing devices as well as supplying a functional infrastructure and network facilities, to a company’s employees. “IT” may also refer to an ISP (Internet Service Provider) in relation to its customers. “Software” refers to computer programs or applications being developed and delivered by an organization.

Measuring Defects in Six Sigma

Based on its roots in quality control, Six Sigma sees defects as unacceptable variations in output. Both the process and the delivered product or service may suffer from any number of defects.

“Customers” are people or groups downstream from the provider, whether other departments or outside clients. A customer’s needs and wants define acceptable software and services. The business may also set its own standards for satisfactory service. Anything that causes an unacceptable service is a defect.

For example, the IT department may have agreed to deliver a network with “99% uptime, every month” to its company. One 8-hour outage in a 30-day month would be 98.99% uptime, and therefore count as a defect.

One situation may present many “opportunities” for defects. Here are five opportunities in a log-on screen for an online application, where we assume the steps should have worked:

Permits a fifth logon attempt after four consecutive incorrect passwords were entered; but it should have frozen the account after the third
Permits verifying a user with a “secret question and answer” protocol, although the account was frozen by an administrator; this should only be available for the “incorrect password” scenario
Permits access to a “Help” screen other than “Help for Log-On”, when the user had not yet logged-on
Does not prompt a user to change passwords on a schedule defined by the administration
Permits a user to re-use the same password every three months; the specification had been for a one-year time period

Six Sigma’s goal is to reduce the process defect rate to below “six sigmas”, or about 3.4 defects per million opportunities.

The use of “metrics” requires gathering the data, performing statistical analysis, and also determining what the results mean.

IT data centres and software providers may already gather many of the statistics and use many of the processes that Six Sigma would recommend. Six Sigma methods may make significant improvements, however.

Usage Metrics

In IT, a “Usage” metric may conjure questions such as “CPU Usage”: whether a physical resource is heavily used or has spare capacity. In this case, “Usage” refers more to how “much” is requested and how much it costs. In the software field, “usage” measures the number of customers and the number of change requests. For example:

Does one department need system availability when all users have gone home?
Which departments make the most requests for changes?
Which software programs receive the most requests for changes?
Which hardware requires the most frequent repairs?
What receives the most customer complaints?

Process Metrics

Some process metrics deal with following administrative functions. For example, are all necessary signatures obtained before a system administrator adds or deletes personnel from a log-in table? Does someone actually audit this critical function, and log the fact?

Software developers are familiar with project-oriented business processes. Obtaining signatures on proposals, requirements documents, and test phases should be second nature in this field. Do some project leaders omit steps without authorization?

Process metrics also measure the costs in hours, physical resources and hard currency. Do some programmers accomplish more in fewer billable hours than others? Does one data centre use more electricity for HVAC (Heating, Ventilation and Air Conditioning) than most? Is one department outstanding for completing development projects on schedule and within budget?

Outcome Metrics

This is often the most visible area of concern. Was the software acceptable, or did customers demand refunds? Did the IT data centre live up to its SLA (Service Level Agreement) with each department?

Poor outcomes, such as those mentioned above, might trigger an executive response when nothing else could.

Benefits of Six Sigma for IT and Software

Often, however, a poor outcome metric is just the starting point for a Six Sigma project to determine the root cause(s) and determine a long-term solution. The Six Sigma approach also incorporates ongoing process measurements to catch problems as they begin, rather than waiting for dissatisfied customers to raise the alarm.

Oskar Olofsson, 2011

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I am a Swedish-based Lean consultant, and the owner of the World-Class-Manufacturing.com web site.

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