Any step or activity that potentially does not add any value to the product/service is called waste in lean manufacturing. The opposite of waste is value. It is something you as a customer will be willing to pay for. There are eight types of wastes in a lean process.

Transport

Any material movement or relocation which does not directly add value to the product or does not support production is termed as transport waste. This is usually the result of a power workplace, improper facility layout, and lack of planning. 

Inventory

Any excess of supply which exceeds the production requirements is termed as the inventory. The base price of the product is directly affected by this waste. Its causes include inaccurate forecasting systems, unbalanced production systems, and poor tracking and planning.

Motion

Like transport waste, motion waste is any movement of staff/crew that doesn’t contribute added value to the product. It is often caused by a lack of visual controls, poor process records, and poor workplace organization.

Waiting

At a workplace, sometimes the events unfold in a way that they do not synchronize very well, resulting in idle time between codependent events. This idle time is called waiting for waste. Major causes of this waste are poor equipment maintenance, skill monopolies, and inconsistent work methods.

Overproduction

Overproduction can be defined as producing more than needed, faster than needed, or before it’s needed. Possible causes include lack of communication, poor planning, low uptimes, and Automation in the wrong places. 

Over-processing

Over-processing, waste includes endless product refinement, excessive information, redundant reviews and approvals, and unclear customer specifications. It is caused by decision making at inappropriate levels, lack of customer input, and inefficient policies.

Defects

The loss of value mostly due to repair, scraps, and rework of a product is called defect waste. It simply deviates the product from its required specifications. Leading causes include Excessive variation in production processes, inadequate tools, high inventory levels, and incompatible processes.

Unutilized talent

The underutilizing of employees in a process is called unutilized talent waste. This can result in the shape of unnecessary work performed by employees that are not engaged well. Also, they start to work in silos, preventing the share of knowledge.