Page 70 - Six Sigma Advanced Tools for Black Belts and Master Black Belts

OTE/SPH
OTE/SPH
2:55
August 31, 2006
Char Count= 0
JWBK119-05
A New Roadmap for Six Sigma Black Belt Training 55
the deployment of Six Sigma, particularly in the Improve phase. Detailed treatment,
however, can be deferred to an MBB program.
5.3.1.3 Queuing
Queuing theory is concerned with understanding the queuing phenomenon and how
to operate queuing systems in the most effective way. Providing too much service
capacity to operate a system incurs excessive costs; however, insufficient service ca-
pacity can lead to annoyingly long waiting times, dissatisfied customers and loss
of business. Within the context of business-improvement, queuing techniques have
frequently been applied to solve problems pertaining to the effective planning and op-
eration of service and production systems. Specific application areas include service
quality, maintenance management, and scheduling. Queuing techniques have been
widely applied in such areas as manufacturing, service industries (e.g. commercial,
social, healthcare services), telecommunications, and transportation. Queuing tech-
niques can play a useful role in Six Sigma deployment, particularly in analyzing and
improving a system providing services.

5.3.1.4 Simulation and modeling
Simulation is an exceptionally versatile technique and can be used (with varying
2
degrees of difficulty) to investigate virtually any kind of stochastic system. For in-
stance, simulation can help to improve the design and development of products as
well as manufacturing and service processes for a wide variety of systems (e.g. queu-
ing, inventory, manufacturing, and distribution). Simulation has been successfully
deployed in DFSS to replace costly preliminary prototype testing and tolerancing.
Also, simulation provides an attractive alternative to more formal statistical analysis
in, for example, assessing how large a sample is required to achieve a specified level
of precision in a market survey or in a product life test. 21 Bayle et al. 22 reported the
approach of integrating simulation modeling, DOE and engineering and physical ex-
pertise to successfully design and improve a braking subsystem that would have not
been accomplished by any individual tool or method alone.
For system operations analysis, simulation is an indispensable companion to queu-
23
ing models as it is much less restrictive in terms of modeling assumptions. Queuing
24
and simulation techniques also play important roles in inventory control and supply
chain management in organizations.

5.3.1.5 Forecasting
Every company needs to do at least some forecasting in order to strategize and plan;
the future success of any business depends heavily on the ability of its management to
2
forecast well. However, the availability of ‘good’data is crucial for the use of forecast-
ing methods; otherwise, it would turn into ‘garbage in, garbage out’. The accuracy of
forecasts and the efficiency of subsequent production and service planning are related
to the stability and consistency of the processes which are, in turn, influenced by suc-
cessful applications of standard Six Sigma tools. Six Sigma tools and methods identify
and eliminate process defects and diminish process variation. Six Sigma also requires