8 Ways to Reduce Downtime Caused by Quality Defects

Table of Contents

8 ways to reduce process downtime due to quality defects which double the work because they are required to repair rejected products in addition to pursuing target output following the production schedule without compensating for an increase in production capacity so that it will be the cause of carry over.

Overview of downtime

Down time is the loss of productive processing time capacity so that targets are not achieved as planned. Sources of down time are conditions outside the standard that should be in each 6M element including machines, manpower, materials, methods, measurements, disasters so that the loss of productive time.

Examples of machine downtime: machine breakdown suddenly, preventive maintenance activities, predictive maintenance implementation, autonomous maintenance activities. The maintenance department as the executor of preventive / predictive maintenance should find alternatives so that the implementation of this maintenance program does not result in downtime for the production process. The solution is for example preventive maintenance and predictive maintenance activities carried out on Saturdays by changing working days.

Examples of man power downtime: employee absences, assignment of employees to other jobs such as participating in HR training, employee operational errors.

Examples of material downtime: material stock runs out, material supply delays either due to limited means of transportation or supplier supply, material under specification.

Example of method downtime: the process does not follow the SOP, tries a new pattern but the results are lower than the standard, thereby reducing the time base because they have to repeat the work.

Examples of measurement downtime: not carrying out inspections of measurement results, inaccurate measuring instruments, limitations of measuring instruments and invalid measurement standards.

Examples of disaster downtime: earthquakes, floods, tsunamis, pandemics.

All down time is a loss that results in not achieving the target and causing a carryover effect.

Downtime due to quality defects

Apart from coming from the 6M element in understanding the source of downtime, there is a separate definition of this downtime, namely down time is the loss of planned time capacity due to product quality defects which causes carry over.

This source of downtime due to quality defects summarizes the perspective of six big losses related to the cause of down time, namely product quality defects which have further impacts in the form of yield / reprocessing.

The other six big losses elements we consider as part of the downtime are caused by 6M elements.

Downtime from 6M elements and from quality defects will both hinder target achievement and cause carry over problems.

Defect and Carry Over are manufacturing KPIs.

KPI (Key Performance Indicator) manufacturing can be illustrated as follows:

• Production supervisor KPI: zero defects, zero carry over. KPI report to assistant production manager every month.
• Production manager assistant KPI: zero defects, zero carry over, zero waste, zero over time. KPI report to manager every month.
• Production manager KPIs: zero defects, zero carry over, zero waste, zero over time, output value, zero accidents. Report this KPI to the general manager every 3 months (quarter).

Actually, workers below the supervisor level also need to have their own KPIs, for example zero absenteeism and achieving individual output so as to make it easier to control the productivity of workers.

8 Ways to Reduce Process Downtime Due to Quality Defects that Cause Carry Over

The target for achieving KPI quality defects is in the form of achieving conditions where there are no product quality problems (zero defects). By getting zero defects, 2 KPIs will be achieved at once, namely quality defects and zero carry over (carry over which is only caused by quality defect problems).

Here are 8 ways to reduce process downtime due to quality defects that cause carry over problems.

1. Understand and find quality defect problems

Quality defects are a serious problem because they are directly related to customer trust and satisfaction. Imagine if the customer no longer uses the product due to frequent defects, then the future of the company can be guessed.

Collect all types of quality defects from the beginning of the process, mid-process and after finishing. Data collection can use QC tools in the form of check sheets.

Quality defect data at least includes the type of defect, number of defects, number of orders, location where quality defects are found.

2. Make achievement targets

This achievement target is the same as the KPI achievement target, namely zero defects. Here it is necessary to set a target priority scale in the order of the largest / most quality defects first. Zero defect priority setting can use QC tools in the form of Pareto diagrams.

3. Make an analysis of actual conditions

The main target has been set in solving the first quality defect, namely the type of defect that occurs most often.

An example of the type of quality defect "scratched goods" after the finishing process in the furniture industry. Create a history based on the number / frequency of occurrence of this type of quality defect in the last 30 days. Pay attention to the tendency of whether the statistics go up or down to be used as a basis for taking the most effective action towards solving it.

To display these statistics, you can use QC tools in the form of a histogram.

4. Make a cause-and-effect analysis

It is more practical to use QC tools in the form of a fishbone diagram (Ishikawa diagram / fishbone diagram). The aspects in each of the sub causes of the fishbone diagram include the 6M elements. Here you can also combine the use of fishbone diagrams with an integrated SWOT analysis for better results.

So confused, he said 6M is the cause of downtime as mentioned at the beginning, here instead 6M is a problem-solving tool, what is this, admin?

6M as an analysis tool in overcoming problems and these problems arise from 6M elements. This means that the 6M element is the source of the problem and to solve the problem is to analyze the source of the cause, namely 6M.

Quality defects are broken down based on each 6M causal factor in order to obtain a bright spot as the main source of quality defects.

5. Create a corrective action plan

In addition to the main source of quality defects, there are other sub causes within the scope of cause and effect point 4 above.

Make groupings so that the sub causes become simpler so that corrective action plans can be effective / efficient.

Take advantage of QC stratification tools to simplify the sub causes of this defect.

6. Implementation of corrective actions

This is an execution creating zero defects. Make sure that everything goes according to plan without a hitch because potential bottlenecks are prearranged.

Implementing corrective actions, especially workers in the production process section, is assisted/directed by the Quality Control team.

In implementing corrective actions, you can use QC tools in the form of a control chart.

7. Examination of repair results

Evaluation of the results of improving the achievement of zero defects. There may be several points of deviation from the planned target, not meeting the target or exceeding the target.

Examine and evaluate all these potential points and then make a pattern of improvement results, whether the statistics are increasing or staying the same as before. Take advantage of QC tools in the form of scatter diagrams to make it easier to map the results.

8. Establish standards and subsequent corrective action plans

The standards set can be in the form of WI (Work Instruction) or SOP regarding the prevention of quality defects. This standard is intended as a benchmark for subsequent improvements to continuously prevent downtime.