The average delivery time of electronic products from Singapore to the USA is 6 days. There are many corporate customers in the USA. Although an average of 6 days, at the customer side there has ever received the goods on day ten, but some are receive the item 4 days, two days faster than expected. There is also up to 21 days of goods not yet reached the hands of the customers.
For example, the service at fast food restaurants, the average time of presentation is 5 minutes. But there who have had the service up to 15 minutes food was not ready. There are also 3 minutes are ready, anyone ever get the service up to 25 minutes. Such example is the service time variation and, if averaged over 5 minutes.
In six sigma project, variance and standard deviation concept holds a very important role in the analysis. This is because of experience in the production processes of goods and services; the variation is a scary thing. The existence of such a large variation will lose credibility and trust of customers to our product or service. Therefore, Six Sigma projects focus on reducing variation, because each customer will sense such variations. If you get the fastest service in the variation of service time, customers in the profitable, and vice versa if the customer get the longest service will think that our company is not professional, and less able to serve customers well.
The core of the reduction of this variation is actually a standard variation as small as possible because, later this standard is input to the next process as well as the next. The higher the variation of the more difficult the synchronization between the departments concerned. Therefore, the specifications of the customer are very important. This specification can be time, cost, quality or quantity.
Support the reduction of variation here would be very complex if done in the production area. All the tools on the reduction of variation will be also related to waste management through lean manufacturing project, basic improvements in production activity through 5s campaign and other quality projects. Clearly this variation reduction projects will not be resolved in one project alone, but must continue and sustainable.