What are the main causes for wasting time in production? How would you solve this problem?

I think the main causes for wasting time is inventory and the untrained worker. 

we can eliminate inventory by modifying our layout or by making the process smooth line and also we can train our worker so that waste can also be reduced

1. Data migration during cutover activities

2. Proper Quality Testing 

i think wasting time is from the worker. A humble worker is very active and early to bed

The main course is "Time management" and I able to apply it by using motion study

I believe main causes of wasting time in production are 

Lack of materials 

shortage of labour 

also not having proper planning to execute and get the result done .sloving these matters should have proper plan .make sure adequate inventory is available all the time and enough labor force.

Not haveing proper lplaning and not having mesured targets for the given tasks.

I will solev this issue by asighning capeble person for the tasks with the target to coplite within the given time.

Not following the schedule. Lack of coordination and/or supplies.

I think the main cause for wasted time in production would be processing errors that derieves from within the process manufacturing stages which can be caused by both machines defects and human errors. 

I think the best way to tackle these is to look at the bigger picture by minimising the inventory and pressure on the machines and staff, while at the same time ensuring to undergo quality management for production. It is also important to provide on-going training to the staff and incentives upon exceptional performance because psychological wellbeing and training will increase the confidence of the workers and it will ensure the risks will be minimised in that sense.

While the best ways to avoid product and machine defects during the manufaturing process would be through ongoing preventive maintainence, inspection advances, production and engineering communication. 

Fix the target for best quality products. Motivate staffs by giving incentives/best employee awards.

Thanks for the invitation.

From the perspective of hardware, usually production delays are the result of delays for the product development schedule. During development, there are four causes of delays, and each have different mitigations.  (1)  Design Changes  (2)  Supplier Issues  (3)  Schedule Optimism  (4)  Failure analysis and Triage

Design Changes - Hardware development is messy and there are always unanticipated issues that are revealed during development builds. It could be an unexpected performance variation, a mushy button, or a devastating reliability test result. The fixes sometimes involved a simple process or SOP (standard operating procedure) change at the factory, but often required a time-consuming PCB spin, tool modification, or new parts.

To find issues that require design changes, minimize the time between ignorance and issue discovery. For example, early discovery of related issues could enable multiple changes to be rolled into a tool modification. Today, product companies send engineers to the factories during development builds to improve their chances of discovering issues early.

Supplier Issues - Parts suppliers and manufacturers sometimes run into trouble producing at the expected quality or rate, resulting in impact to build schedules. For example, a supplier may cherry-pick parts (make 5000 to deliver 50 without communicating that the yield is 1%) in an effort to keep the customer happy while trying to solve the issue internally. It won’t be possible for this vendor to deliver 500 to the next build, but sometimes the team will not find out until the parts do not show up. This lack of transparency prevents the team from being able to seek alternatives to keep the schedule on track.

When issues are highlighted early enough, engineers can be dispatched to the supplier sites to work on the problems together. If design changes are needed, they can often be kicked off then and potentially still make the scheduled build. Plans can be put in place to bin or sort parts in order to get through the build and buy more time to fix the issue.

Schedule Optimism

While it varies from industry to industry, consumer electronic products are plagued by highly optimistic or “line-to-line” schedules. These schedules do not account for iteration. When the inevitable hiccup arises, the team will have to adjust by de-featuring the product, spending more money to expedite, or delaying.

The solution here is to design time into the schedule to iterate — but it’s easier said than done because almost all hardware products are being made for a certain market window (Christmas, Dads and Grads, Back to School, etc).

Failure Analysis and Triage

Although counter-intuitive, the failure analysis process itself can be a place where significant time is lost. For any issue, there are often several potential root causes: part quality, workmanship, process, design, etc. Each of these has to be systematically proven or disproven in order to make progress on the issue.

In development builds, failures are expected, so product engineers are often on-site at the factory to look at failures and assess root cause. Sometimes, even with a pile of units to dissect, the engineer does not have all of the data he or she needs to fully prove or disprove a root cause, and additional experiments are suggested as a next step to collect this information. Engineers are notorious for requiring evidence disproving all other possibilities before they will admit that the design may be at fault and needs to be changed. As a corollary, the factory is often unfairly pegged as the first culprit, no matter the issue, and has to spend resources to prove that their process is not the root cause. Even without politics, this process is not fast -- so the heaviest yield hitters are addressed first, and sometimes in development the onesie-twosie failures are ignored altogether.