5 Steps to defect-free Windows & Doors

Quality Control takes planning, training, and even company culture changes. None of it is easy, but the cost of Non-Compliance and poor quality is a killer.

However, Quality is not only Free; Quality Pays.

5 Basic Concepts/Steps for a Simple, Cost-effective Quality Control Program

1 – Define your “Customer – Supplier” Pairs.

The first step is a mindset change, and it is necessary to identify What to Quality Control.

  • The basic concept is simple: when you do a job, you need to know who your customer is and what they need.
  • Salespeople must be specific in identifying the customer’s needs.
  • The worker who receives the profiles needs to know what the saw operator expects the profile to be like.
  • The person at the welder needs to know what the corner cleaner needs.
  • The corner cleaner needs to know what the hardware Station will look for.
  • The Screen Department needs to know what the Assembly station requires.
  • And so on…

Your entire Operation is a series of Supplier to Customer relationships. We call these Customer-Supplier Pairs.

2 – Create Compliance Rules for each Window/Door Series, Product, Assembly, and Part.

The next step is to identify what each “Customer” requires from its Supplier.

This information forms the basic Quality Compliance Criteria you need. Gather this information by product, part, option, and assembly.

In OpenJanela, we add this information to our Quality Compliance Rules; it could be presented in quality control spreadsheets in a manual system.

The fact is that a Quality Check for a Casement Window will be different than one for a Patio door, so it is important to do this for every product.

There are two types of Quality Control Parameters:

(In a manual system, use simple printed QC Cheat Sheets for each Station)

Pre-Processing QC Checks

  • Check Quality before adding any Labor or Material to a Part/Assembly.
  • If the Part/Assembly fails the QC check, it is immediately either remade or fixed.

This will prevent you from adding cost to bad parts or assemblies.

Example: Sash Hardware Placement Station

At this station, the Operator receives assembled, cleaned sashes from the Corner Cleaner.

Some potential checks could be:

  • Quality of the Cleaned Corners
  • Quality of the Weld – No visible cracks
  • Quality of the Profile – No obvious scratches or damage

Post Processing QC Checks

Check the Quality of the Part or Assemblies and make sure it conforms to what the next station expects.

Example: Sash Hardware Placement Station

OpenJanela displays a list of parts an operator needs to add to the Assembly. The system will also display the List of Quality Criteria that the next station expects. The operator will check each criterion and accepts or reject the assembly.

  • Quality of the Assembly: No Visible Scratches
  • Quality of the Installed Hardware: No Scratches on hardware

3 – Use Random Sampling For Large Volume Parts:

Random sampling is an ideal way to check the quality of large volumes of parts.

It assumes that all the parts were checked by the supplier (or previous station), so checking every part is unnecessary.

When you select parts randomly and enough parts (Sample Size), you can establish a percentage of defects.

Your “Level of Confidence” will increase with bigger sample size and proper randomization.

OpenJanela users can set the desired Confidence Level for the quality control process in Preferences. The system will randomly prompt operators to select parts to check. The system will do so enough times to select the Total Number of Parts (sample size) necessary to meet the desired Confidence Level.

4 – Final Quality Control Station

All products leaving the production floor need to be checked.

The list of questions at the Final Assembly should be more encompassing than those asked at processing stations.

OpenJanela’s QC Station changes dynamically based on Product Type, Options, and other factors important to Quality Control.

5 – Use simple statistical tools to analyze QC Data

Use simple Statistical Process Control to identify the frequency of Non-Compliance.

For example:

  • How many times were corners not cleaned?
  • How many times do welds fail, on which profiles, and at which welder?
  • Day/time of occurrences (time of day, season, supplier issues, etc.)?
  • Which operator was involved (to identify training or other issues)?

Such data may reveal issues and causes that are not entirely obvious. Armed with this data, you can take steps to rectify issues and prevent them in the future.

Quality Control is an ongoing process. Creating your ultimate program may take a few iterations and refinements.

Please contact me with your questions – No strings attached. I would love to hear your ideas, opinions, and concerns!

At OpenJanela, we understand that no two clients are the same. We customize quality control programs into our paperless factory production system. OpenJanela is built for the way You do business.

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