Today I have been...
(continued)

Reading about Y2X. It builds on the I/O of SIPOC charts and can be done ahead of other improvement methods and techniques. A matrix with outputs on the Y, and inputs on the X it shows how I's influence O's.

The next is Taguchi methods which are used for optimising product and process, and pre-manufacture design tests.

It is very heavy on statistical methods (more than are covered in T889) and I am concerned that so many of these methods seem to focus on production process improvement, rather than service or even "intangibles" such as software. See S10.5 in B3, there is much material.

SMED is next up, and is closely associated with lean but can be used on its own to help solve throughput problems, according to the text. Often, it is used in batch manufacture to help reduce the inter-batch time gap (the name comes from a process like this - single minute exchange of dies)

Process redesign is covered next and this definitely can be used for services. The starting point for this activity is to use something along the lines of activity sequence diagrams, flow-block diagrams, flow process diagrams or spaghetti charts (all covered in t889) to model the existing process. It's also important to understand the customer interface "touch points" for service processes. The text focuses on throughput time analysis and bottleneck analysis. Slack (2007) lays out principles of an "improvement-oriented approach" to process redesign. An interesting point is that "an hour saved at a non-bottleneck is a mirage. Non-bottlenecks have spare capacity anyway. Why bother making them even less utilised?" and another is that something is only utilised if it contributes to the entire process, in other words if it spends 100% of its time on value-add activity.

Slack's points on page 99 & 100 of the block seem to be extremely pertinent and useful.