In the production process the forming of waste should be kept at a minimum, to save on resources and therefore costs, but also on waste transportation and disposal costs. Jan-Henk Welink discussed the three types of waste that are formed in the production process.

Main takeaways

In production three types of waste are formed:

1. Products that are not according to specification.  Off-spec products are minimised by improving the continuous cycle of plan-do-check and act (described in ISO 9000)
2. Wasted materials that are directly related to the process. Find customers for these types of residues by a market study. Regard them as by-products.
3. Waste that is indirectly related to the process. Offer convenience in separate waste collection. Check large obsolete products (furniture, computers) first on reusability.

Failing products in a bathtub

The failure rate of a product is an important factor that determines the life expectancy of a product. Reducing the failure rate means improving average life span. A visual model for the failure rate of a product in its product life is the Bath Tub Curve (especially electronics).

Figure 1: Bath Tub Curve explaining failure rates in a product life cycle

 

The Bath Tub Curve divides the product life in three periods:

1. Burn in: product is new, failure due to errors during production and transport

2. Use full life: Product fails in “normal” use by consumer

3. Wear out: Product fails on end of expected life

 

With the following failure causes per product period:

 

Burn in period     

• Poor quality control
• Poor test specifications
• Inadequate manufacturing methods
• Substandard materials and workmanship
• Poor debugging

 

Useful life period   

• Low safety factors
• Undetectable defects
• Abuse
• Natural failures
• Higher random stress than expected
• Wrong application

 

Wear out period

• Wear due to aging
• Corrosion and creep
• Short designed-in life
• Poor maintenance
• Wear due to friction
• Wrong overhaul practices