It has been a matter of discussion in many international organizations of whether Six Sigma and lean Six Sigma mutually exclusive to each other or not. While engineer Bill Smith of Motorola was the mastermind behind Six Sigma, Toyota Production System (TPS) used the Lean Six Sigma mechanism effectively for the very first time. Lean Six Sigma focuses on creating better flow, eliminating wastes, and taking unnecessary time out from various processes. Its essence could be summarized by saying that it aims at shortening the entire timeline from the time of receiving order until the collection of cash for the services or goods provided by them. 

Getting back to traditional Six Sigma it focuses on defect reduction in the commercial and industrial processes as it can provide companies a competitive advantage in the market. This concept is the foundation around which the strategies of Six Sigma are built. Comparing Six Sigma and Lean Six Sigma, we can understand the basic difference, which is the former aims at reducing variations while the latter aims at reducing wastage. While achieving 3.4 defects per million processes is the definition of perfect process performance in Six Sigma, improving the speed of the occurring processes is the main focus of Lean.

Six Sigma improves the poor quality cost, whereas lean deals with the improvement of operating costs. But, the difference lies in the learning curve with Six Sigma having the longer learning curve and lean having the shorter one. Value stream mapping is used by Lean, whereas various improvement process approaches are used by six sigma. Lean project steak one week to 3-month fairness Six Sigma projects take two to six months for completion. 

Lean projects are driven by demand, while Six Sigma projects are driven by data. The complexity levels of Six Sigma and lean projects are very complicated and moderately complicated, respectively.

What should an organization use among these two to improve?

The best way for a business or an organization to improve is by the appropriate mixture of both Six Sigma and lean methods. The application of lean should be proceeding and coexistence with the Six Sigma method application. Repeatability and stability are ensured in basic processes by lean. The variations caused by human processes tend to go away once stability is achieved. Upon stability, the collected data becomes more reliable for Six Sigma activities to function more accurately. A linear continuum can depict Six Sigma and lean tools with Lean Six Sigma in the middle of them.

Major business problems:

• Waste is abundantly present.
• Redundancies and inventories need to be minimized.
• The workflow needs to be improved.
• Processes should be sped up.
• Human mistakes should be avoided.

Utilization of Lean tools:

1. Process simplification- Processes ought to be very simple as complex processes require a task force of highly trained professionals to execute necessary activities for the processes. Lean tools make this simplification possible.
2. Speed increment- Speed is an effective competitive advantage as its improvement correlates directly to customer satisfaction. 
3. Improvement in Flows- Bottlenecks are most likely formed if is the product flow in the production phase is not showing streamline movement. If bottlenecks are not eliminated, they will cause more ideal time lapses. So, it is better to treat it with Lean tools to improve the flowing efficiency.
4. Inventory minimization- the most critical aspects of any given process are the inventories used. Wearing and tearing of raw materials, real estate cost getting higher, and many other problems occur because of larger inventories. Similarly, raw materials become unavailable, and productions are forced to halt sometimes if smaller inventories are used.

Defect-less Processes:

Mistake elimination in processes becomes very simple when lean is involved. But for that to be fruitful, the following attributes should be exhibited in the organization:

• Intense quality issues.
• Exercise variation in the organizational phase
• Complex problems are being displayed.
• Identification of challenging root causes of problems
• Technical considerations are present in a huge amount.

Six Sigma tools could help in these cases by:

• Variation minimizing.
• Application the scientific problem-solving tactics
• Project chartering goes through robust utilization.
• The complete focus over quality issues
• Technical methodology for employment.

A combination of issues from both the sets has been recognized by executives of many companies. A more synergistic and Holistic approach towards problems is reflected by lean six sigma being placed in the middle of the continuum. A broader selection of approaches is found in Lean Six Sigma, which can deal with money terrible problems arising in a company and its production.