What are Lots on hold?

Lots on Hold are lots that are temporarily suspended during testing due to a concern about yield, the failure rates of certain bins or the quality of testing. Parameters are set and when a lot exceeds the limits the lot is put on hold and investigated.

How are they typically handled?

When something is askew, the lot is put on hold. The technician on the floor investigates. Typically the technician is not the product expert. 

The technician has a template where they describe the problem. They send it to the person or team familiar with the product. The person could be in a different timezone, country and speak a different language. They must wait until the person gets the message, deciphers the error message, figures out what happened, and decides the next steps, then relays the message back to them.

How can yieldHUB help?

yieldHUB helps automate the communication of Lots on Hold for you, to save time, enhance collaboration and reduce human error. It allows your team to spend less time filling out forms and waiting for answers. They will spend more time doing value-added activities. 

Dashboard: Rather than your technician completing a form, yieldHUB presents any lots on hold in a dashboard that you can bookmark. 

Comparison with good lots: In one click you can compare lots on hold with good lots. yieldHUB automatically knows good lots and provides an in-depth report comparing good and bad.

Visualization: yieldHUB displays the comparison data in chart and graph form identifying the bins and tests that have most changed in the lot on hold. 

Collaboration: The lots on hold dashboard is on-line and can be used by multiple engineers concurrently. Whoever signs off a lot will justify it with a comment and for an audit trail. Other engineers can add their own comments also. This is especially useful in a high focus product release which may have teams in different countries.

Knowledge-base: The yield management system stores the information for you so you develop and archive over time, for each project type, or customer. When a lot is put on hold, the technician can look at stored solutions in the knowledge base about previous incidences of the issue and make decisions based on what happened the last time. 

Other benefits: yieldHUB’s other core benefits are speed, scalability and security. By choosing yieldHUB for Lots on Hold you will benefit from these principles. 

Next level: In some cases, we can introduce yieldHUB into a company’s factory floor hardware or production line by integration with your factory floor (MES) system.

If Lots on Hold are holding you back, we can help. yieldHUB helps thousands of people every day. Contact us at any stage for a demo or chat about yield management and lots on hold. 

Pages 71 and 72 of the USA Department of Defence document MIL-PRF-19500P of 10 April 2014 requires manufacturers of JANS products to implement controls on lots, to detect and reject maverick lots. Specifically, an extract of D.3.9.5.h.3 of the above specification states:

” The manufacturer shall ensure that the lot’s mean and standard deviation is consistent with
previous lots. After initial qualification a minimum of 5 lots must be statistically monitored for spread and location. Significant changes between lots for average and standard deviation shall be addressed by engineering comment. Lot-to-lot variation control in spread and location shall be performed for each critical parameter. Control shall be based on a moving average of at least 5 lots, see D.3.9.1. This control is for comparing lots only ….”

This specification is implemented in yieldHUB as follows. It avoids any analysis in a spreadsheet which would take hours otherwise and would be subject to human error.

Lots are automatically placed on a dashboard for review by engineers.

  1. They can select up to 10 lots of a JANS Part Number to be analysed for variation at a time
  2. If they select only one lot, the latest 10 which are not found already to be Atypical
    i.e. described as  “Approved-Atypical” or equivalent, are loaded into the report to be
    compared with the one you selected
  3. Any of the lots can be assigned a status “Approved”, “Pending” and “Approved-Atypical” in the yieldHUB database based on the engineers review of the statistical performance of each lot
  4. User can search the database for lots with a given status

Can yieldHUB Help You?

Contact yieldHUB today! Our global sales and support team will be happy to help.