What is Non-Productive Time (NPT) - How to Track NPT?

Non-Productive Time (NPT):

Non-productive time is the hours you have to pay an employee for, when he is not producing the product.

The term NPT in industrial engineering is non-productive time. The time an operator spends not producing any garment is called unproductive time. In garment manufacturing, non-productive time is measured to analyze how much time lost to others is lost due to machine downtime. A report is generated by recording machine downtime or any lost time called NPT report. This is the essential MIS report where the factory values ​​every standard minute to its operators.

In most factories, industrial engineers or line managers are responsible for recording the NPT. Industrial engineers performing line-wise NPT analysis for factories. They are used in printed format to record non-productive time. Non-productive time criteria include where major time is wasted.

Lost time is recorded with signature of concerned person and corrective action plan to demonstrate to management for low production and efficiency on a given day. Below are some examples of lost time

•     Line Setting - Time lost while setting up lines for new styles.
•     Machine breakdown
•     Cutting is not available
•     Stitching quality issues
•     Cutting quality issues
•     Power failure
•     Change in feeding plan
•     input gap
•     Strip up and down
•     cutting problem
•     Meetings and training
•     Air compressor problem
•     Accessory supply issues
•     cut wrong
•     Shading problem
•     Clean the machine
•     Quality issues
•     rework
•     Operator not provided at correct time
•     needle breakage
•     Fire alarm

Calculation of NPT.

Provide an NPT configuration on each line. The line supervisor is responsible for recording lost time with appropriate codes. If you find that machines are idle during production, find out the reasons for the idle time and note the start time and end time as shown in the format above. If multiple operators are sitting idle for the same reason, multiply the time lost by the number of operators to calculate the total man-minutes lost and record in your NPT format. You need to get the signature of the person concerned along with the corrective action plan.

Lost time recorded under the section must be approved by the HOO or authorized person.

Calculate the total lost time in each section at the end of the day.

Pie chart of NPT factor

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

Use of NPT reports for process improvement.

Once you collect a line lost time report for a month you can analyze and find out which NPT parameters are occurring at high frequency. You will get a clear picture of how many man hours are wasted due to the presence of those NPT parameters in the process. All these lost man-minutes can be converted into productive minutes by improving processes and robust production planning. Now you have to think about reducing the main lost time parameters. Analyze root causes for lost time and take an improvement project to reduce valuable standard hours.