Theory of Constraints and Six Sigma

What is Theory of Constraints (TOC)?Sigma project to reduce defects in it by keeping the
The theory of constraints helps manage complexmachine in the optimal condition can be the strategy
systems, as well as determine the root cause of anyfollowed).
problem. Contrary to Six Sigma, the approach is logic3. Subordinating everything else to the decision made:
driven to analyzing the root causes. There is aThe next step is to adjust or eliminate those activities
probability of a Six Sigma project failing due to wrongthat may hinder the utilization of the constraint to its
selection.maximum capacity.
The TOC approach is to manage and identify4. Elevating the constraint: If the system performance
constraints of the systems; its strength is the qualitativeis not satisfactory, efforts or investment should be
analysis, which is useful in dealing with highly complextaken to improve or eliminate them.
situations. The processes are made powerful enough5. A broken constraint: When one constraint has been
to deal with the variations. The Six Sigma approach todealt with, move on to the first step of the cycle to
value is that of meeting the customer requirements,handle other constraints. Ensure that old policies and
while that of TOC is that of using the constraint tohabits are evaluated in relation to the changed
define the maximum value for a customer in relation tocircumstances.
the constraint.The combined utilization of Six Sigma techniques and
Six Sigma effectively combines with TOC. Though thetheory of constraints can work wonders for the team.
two approaches are different to a certain extent, theyIn the first step of project selection, the theory of
can be very powerful if implemented together. Sixconstraint helps the Six Sigma team to choose the
Sigma improvement based on TOC methodologycorrect project without wasting Six Sigma resources
addresses the constraints that exist in systems, ason strong areas.
well as future constraints that may arise once theThe Six Sigma methodology applied on the weak part
current ones are dealt with.will help reduce the defects and maximize quality.
The five basic steps of TOC are:Additionally, the theory recognizes the constraints in
1. Identifying constraints: The first step is to find out orthe beginning that helps avoid wastage.
look for any constraints if they exist in the system.Additionally, those areas that are working properly are
2. Determining strategy to exploit the constraint: Oncenot touched and new tools and techniques used to
the constraints are identified find out a Six Sigmarepair or replace the existing constraints. Rather than
project which will help minimize waste of the constraintreplacement, a resolution of problem should be found,
by utilizing the constraint itself.as replacement would mean wastage in itself.
(e.g. if a machinery in use is a constraint, then a Six