What is non-productive time(NPT)?|How to track NPT|How does it work in apparel industry?

 

What is non-productive time(NPT)?

Non-productive time is the hours you must pay an employee for,when he or she not producing the product.

In Industrial Engineering the term NPT is Non-Productive Time. The time that is spent by an operator without producing any garment is called nonproductive time. In garment production, non-productive time is measured to analyze how much time is lost due to machine downtime of others lost time. A report is made by recording machine downtime or any lost time is called NPT Report. This is as essential MIS report where factory value each standard minute of its operators.


In most of the factories, Industrial engineers or Line Managers are responsible for recording NPT. Industrial engineers are analyzing line wise NPT for the factory. They are used Printed formats to record non-productive time. Non-productive time includes criteria where major time lost.

 

Lost time is recorded with signature of respective person and corrective action plan to show management a reason for low production & efficiency in a particular day. Some example of lost time is given below

• Line setting - time lost at the time of setting up the line for new styles. 
• Machine Breakdown 
• Cutting not available 
• Stitching Quality issue 
• Cutting quality problem 
• Power failure 
• Change of Feeding Plan 
• Input gap
• Stripe up down
• Cutting problem
• Meeting and training
• Air compressor problem
• Accessories supply problem
• Cutting mistake
• Shading problem
• Machine cleaning
• Quality problem
• Rework
• Operator not given at right time
• Needle breakdown
• Fire alarm

 

A  NPT format has been shown in the below for your reference. NPT reasons may be different in your factory. So make your own list of NPTs those occur frequently in your factory.

Fig: Non-Productive Time Recording Format

 

Calculation of NPT.

Provide a NPT format to each Line. Line supervisor are responsible to record lost time with appropriate code. If you see machines are idle during production hours, find out the reasons of idle time and note down start time and end time, as shown in the above format. In case multiple operators are sitting idle for the same reason multiply lost time by number of operators to calculate total man-minutes lost and record on your NPT format. You have to take signature from corresponding person with corrective action plan.

Lost time recorded under the category need to be approved by HOO or authorized person.

At the end of the day calculate total lost time in each category.

Pie chart of NPT reason

Make a pie chart to visualize the NPT percentage of all department. In this pie chart we can see the highest NPT% with respective department. Management can easily see the clear scenario the highest liable department. 

 

Use of NPT report for process improvement.

Once you have collected lost time report of a line for a period of a month you can analyses and find which NPT parameters are occurring at higher frequency. You will get clear figure how many man hours are lost due to presence of those NPT parameters in the process. All these lost man-minutes can be converted into productive minutes by improving processes and strong production planning. Now you need to think upon reducing the major lost time parameters. Do root cause analysis for occurring lost time and take an improvement project to reduce valuable standard hours.