FabTime Cycle Time Management Newsletter Abstracts

FabTime Cycle Time Management Newsletter Abstracts - Volume 24 (5 issues)

Cycle Time Improvement for 300mm Fabs (Issue 24.05)

Welcome to Volume 24, Number 5 of the FabTime Cycle Time Management Newsletter. In this issue, we have a quick recap of the recent Fab Owners Alliance meeting, an announcement about FabTime’s new chart engine, and a variety of articles from Jennifer’s LinkedIn. Our software tip of the month is about using our Process Time Lot List and Tool State Gantt charts to analyze lot cascading, with the goal of driving improvements in tool utilization.

In our subscriber discussion forum, we share poll results on a question about top contributors to fab variability. We also share a subscriber question about managing the cycle time of external processes and a response to our recent software tip of the month about using smaller carts. We also share an example of a chart requested by a prospective customer for assessing the cycle time impact of hot lots.

In our relatively brief main article, we respond to a question from a subscriber who asked which of our recommendations are more applicable to 300mm fabs vs. less automated 200mm and smaller factories. We categorize some operational differences between these factories and share a few recommendations for 300mm (and highly automated 200mm) fabs.

Commonly Reported Wafer Fab Cycle Time Contributors (Issue 24.04)

Welcome to Volume 24, Number 4 of the FabTime Cycle Time Management Newsletter. In this issue, we have a Semicon West wrap-up and announcement about the upcoming Fab Owners Alliance meeting, a call for papers for the 2024 Advanced Semiconductor Manufacturing Conference, and various news links from Jennifer’s LinkedIn. Our software tip of the month is about using sparklines (very small, data-dense charts) to convey large amounts of information in a single dashboard. We have a plethora of subscriber discussion topics ranging from a timely question about AI/ML to tool queue times and control plans to a response to the prior issue about forward-looking cycle time metrics.

Because of the large quantity of subscriber topics, we have included a relatively short main article. Over the years, we have surveyed people on our website and in our cycle time management course, and more recently via LinkedIn, about what they see as the primary drivers of cycle time for their fabs. We share highlights from these responses, with some thoughts from Jennifer on why the complexity of fabs makes them so interesting.

Forward-Looking Cycle Time Metrics (Issue 24.03)

Welcome to Volume 24, Number 3 of the FabTime Cycle Time Management Newsletter. It’s been an exciting time for FabTime of late. In this issue we have announcements about two new FabTime employees, a new video and page for requesting software demos, and our first-ever booth at SEMICON West. We also have a plethora of subscriber discussion, ranging from responses to last month’s cycle time tip about reducing the number of hot lots to selecting fab dispatch rules and making plans for particle checks on multi-chamber tools.

In our software tip of the month, we show how to vary the x-factor on a projected lot completion chart to do what-if analysis on the lot’s future cycle time. This tip ties in to our main article, which is about forward-looking cycle time metrics for wafer fabs, something a number of our customers and subscribers have been interested in recently. We discuss the use of planned cycle times to forecast completion dates for individual lots, and then review three different metrics that each predict future average cycle times based on current fab performance: dynamic x-factor, summed operation cycle time, and turns-predicted cycle time (a new metric based on WIP turns). As always, we welcome your feedback.

Managing Time Constraints between Process Steps in Wafer Fabs (Issue 24.02)

Welcome to Volume 24, Number 2 of the FabTime Cycle Time Management Newsletter. In this issue, we have an exciting staffing update about the promotion of Lara Nichols to become FabTime’s President. We also have an announcement about our recent collaborative case study with Flexciton at the Fab Owners Alliance meeting, as well as the usual updates from Jennifer’s LinkedIn. Our software tip of the month includes two ways of measuring the duration of downtime events, following up on a tip from the last issue.

We have a plethora of subscriber discussion in this issue, including calculating theoretical cycle time, X-Factor, and the value of a day’s worth of cycle time, as well as managing bottlenecks. Our final subscriber question, about managing a process sequence with time constraints between steps inspired us to make time constrained processing the topic of this issue’s main article. Jennifer studied time constrained systems for her PhD research and has been remiss in not delving into this complex topic sooner. She discusses capacity planning methods for time constrained systems, then moves on to operational issues, and closes with a few recommendations for coping with time constraints in practice. As always, we welcome your feedback.

10 More Recommendations for Improving Fab Cycle Time (Issue 24.01)

Welcome to Volume 24, Number 1 of the FabTime Cycle Time Management Newsletter. In this issue, we have an announcement about a case study that we’ll be presenting at the Fab Owners Alliance next week, an update about our efforts to change the platform that we use to send the newsletter, and an announcement about new training and informational materials for software customers. Our software tip of the month is about using the newly modified Dynamic X-Factor chart in FabTime. We have subscriber discussion about the best way to share alerts, how to identify bottlenecks in the fab, and whether to set a lower bound on the number of hot lots.

Our main article this month was inspired by the positive response that we’ve received to our new cycle time improvement tip emails. We shared a list of ten recommendations for improving fab cycle time two years ago, and today we introduce ten additional recommendations. While not all these recommendations will be relevant for all readers, we hope that each of you finds something useful in the discussion. If you have additional tips for improving fab cycle time, we would love to compile and share those in the future.