22 Dec 2013

Cost of Quality (COQ)

"The cost of quality.” It’s a term that’s widely used – and widely misunderstood. The “cost of quality” isn’t the price of creating a quality product or service. It’s the cost of NOT creating a quality product or service.
1. Every time work is redone, the cost of quality increases.
2. The reworking of a manufactured item.
3. The retesting of an assembly.
4. The rebuilding of a tool.
5. The correction of a bank statement.
6. The reworking of a service, such as the reprocessing of a loan operation or the replacement of a food order in a restaurant.

                In short, any cost that would not have been expended if quality were perfect contributes to the cost of quality.

Elements of quality cost
Prevention Costs
The costs of all activities specifically designed to prevent poor quality in products or services.

Examples are the costs of:
1. New product review
2. Quality planning
3. Supplier capability surveys
4. Process capability evaluations
5. Quality improvement team meetings
6. Quality improvement projects
7. Quality education and training

1. Appraisal Costs
The costs associated with measuring, evaluating or auditing products or services to assure conformance to quality standards and performance requirements.
These include the costs of:
1. Incoming and source inspection/test of purchased material
2. In-process and final inspection/test
3. Product, process or service audits
4. Calibration of measuring and test equipment 
5. Associated supplies and materials

2. Failure Costs
The costs resulting from products or services not conforming to requirements or customer/user needs. Failure costs are divided into internal and external failure categories.

3. Internal Failure Costs
Failure costs occurring prior to delivery or shipment of the product, or the furnishing of a service, to the customer.

Examples are the costs of:
1. Scrap
2. Rework
3. Re-inspection
4. Re-testing
5. Material review
6. Downgrading

4. External Failure Costs
Failure costs occurring after delivery or shipment of the product 
and during or after furnishing of a service to the customer.
Examples are the costs of:
1. Processing customer complaints
2. Customer returns
3. Warranty claims
4. Product recalls

5. Total Quality Costs:
The sum of the above costs. This represents the difference between the actual cost of a product or service and what the reduced cost would be if there were no possibility of substandard service, failure of products or defects in their manufacture.

Analysis Techniques for Quality Costs 
              The quality system must involve the more than inspection & test in the manufacturing place; every department has a responsibility for assuring that the customer quality requirements are met. The responsibilities for quality must be clearly assigned. Quality is everyone’s responsibility e.g.:

Marketing
Determine the customer’s quality requirements; investigate customer’s opinion of product quality & performance etc.
Engineering
Design quality & safety into the product to comply customer’s requirements, prepare specification.
Manufacturing
Manufacture & deliver products that comply with the drawings & specifications.
Quality Assurance
Assure that the product meets the customer’s quality requirements, establish economical controls for preventing defective products
Purchasing
Select quality suppliers, keep them informed of quality requirements, work with them to correct quality problems.

Finding Quality Costs
          When quality costs are displayed to managers who have not been exposed to the concept, the initial question likely to be “should they be” or “how does this compare with other organizations or products?” unfortunately it is not practical to establish any meaningful absolute standards to such cost comparison.
           A quality cost system should be “customized” to particular company’s needs, so as to distinguish trends of significance and furnish objective evidence for management decision as to where assurance efforts should be placed for optimum returns. 
            The search for industry guidelines or other standards of comparison, quite natural, is quite dangerous, since it leads to quality cost emphasis for “score carding” instead of utilization as management tool for improving the status quality.Analysis techniques for quality cost are reviewed but trend analysis and Pareto analysis are most common techniques.

Trend Analysis
          Trend analysis is simply comparing the present cost levels to past levels. The data should be plotted in several ways. Costs associated with each element grouping (prevention, appraisal, internal failure and external failure) should be plotted by month as total Rs. and as a function of several measurement base thought to be appropriate for future use as indicators of business activity. Elements contributing a high proportion of the costs within a grouping should be plotted and analyzed separately. This will give the information about particular element required to be analyzed in detail to determine the route causes. It is suggested that cost data be collected at least one year before attempting to draw conclusion.

PARETO Analysis
            The Pareto analysis technique involves listing the factors that contribute to the problems and ranking them according to the magnitude of their contribution. In most situations, a relatively small number of causes / sources will contribute a relatively large percentage of the total cost. To produce the greatest improvement, efforts should be put in reducing costs coming from the largest contributors.

The team approach
            Once a problem has been identified and reported, action by the people starts. The efforts of people involved must be planned, coordinated, scheduled, implemented and followed up. Problems can be of two types:
          Those which one individual or dept. can correct and those requiring coordinated action from several activities in the organization. Examples of the first type of problem are operator controllable defects, design errors & inspection errors. Examples of the second type are product performance problems for which a cause is not known, defects caused by a combination of factors not under the control of one dept. and field failures of unknown cases.
         To attack and solve problem of first type, an elaborate system is not required. Most cases can be resolved at working level with the engineer, or other responsible parties.
         Problems of second type are not as easily solved since solution may require action from several sources.One of the best devices for doing this is the quality improvement committee.
         The committee develops the plan, coordinates and schedules the investigation and action. Meeting should be held regularly and minutes published.

How to reduce Failure cost
           There are four steps to an effective corrective action programme.
1.  Make all persons concerned aware of the problem and its possible causes
2. Create a desire in others to solve the mutual problem
3.  Plan and carry out a logical investigation of the problem with others involved
4.  Follow up on action taken.

The quality engineers must assure that data for investigation is providing factual information and should investigate the problem to the extent necessary to define the problem and uncover some of the possible causes.
The description of problem should include its effect on costs, schedule or product quality. Quality performance report should be sent to people who can perceive the investigations and initiate actions to correct the identified quality problem.
The report should be sent to other departments and to higher management also to keep management informed of the status of quality, which will help in formulation of QIT and taking necessary action for completing project.

Check List for reducing Failure cost
1.  Are all the causes of high cost elements known and reported to those responsible for action?
2.  Are all the basic cause of defects found and corrected, or does the action taken tend to be screen out the defective after they are made?
3.  Is nonconforming material salvaged economical?
4.  Is there a coordinated quality improvement efforts     involving all the necessary departments?
5.  Does the program have the continuing interest and support of the functional department managers and G.M.?
6.  Are all cases of high cost field complaints identified and is action being taken to prevent recurrence?
7.   Are all returned products economically handled, repaired and returned to the customer?
8.   Are all warranty charges audited for validity and action taken as necessary?

Prevention of quality cost
           Prevention of quality costs is the responsibility of every department.  Some examples are given below:
1.  Accurately determining the customer’s quality requirements and accurately reflecting them in internal ordering information and design specification (MARKETING)
2.  Designing a product, which is safe, reliable and can be profitably manufactured satisfying customers, needs (DESIGN)
3.  Preparing drawings and specifications which clearly and accurately describe the design and quality criteria (DESIGN)
4.  Is the product capable of meeting quality standards required (QUALITY)?
5.  Can we perform tests and inspection with the equipments we have? (QUALITY)?
6.  Data reporting and corrective actions activities
7.  Can audits be used instead of 100% inspection (QUALITY)?
8.  Getting material from suitable suppliers (PURCHASE)
9.  All training programmers providing a profitable return (TRAINING)

How to reduce the appraisal cost?
             The cost of appraisal some times approaches half of the total quality cost.
1. Are all inspection points located to maximize the return on money spent for inspection?
2. Are all inspection status and method engineered for the most efficient work accomplishment?
3. Can inspection and test operations be economically automated by using special purpose instrumentation or computer controlled equipment?
4. Can inspection and testing record & data reporting function be more effectively performed using computer?
5. Is it possible to control processes sufficiently to prevent production of defective and eliminate product inspection?
6. Can SPC techniques be profitably used?

Optimal Price Analysis
          The Optimal Price Analysis is a mathematical computation that helps a business identify the point where it realize the maximum of profit.
         This Optimal price calculator allows a business to accomplish the following:
Determine the quantity it needs to produce or sell in order to realize the maximum of profit;
Determine the selling price it needs to charge for a specific quantity you sell in order to realize the maximum of profit.
Definitions and terms used in the Optimal Price Analysis

Variable Cost per Unit: the cost that vary with the production or the purchase of one unit.
Fixed Cost (FC): the cost that remains constant within a range of production or sales, regardless of the number of units produced or sold within that range. Typical fixed costs are: rent, mortgage, equipment, salaries, insurance, fixed utilities (office utilities) etc.
Current selling price: the price that a unit is currently sold for.
Current selling units: the number of units currently sold or produced.
Maximum capacity (Units): the constraint regarding the maximum number of units that the company can produce or sell.
Maximum financing capacity: the constraint regarding the financing capacity of the company (bank accounts, credit cards, lines of credit etc.).
Price elasticity of demand (PeD): the responsiveness of the quantity demanded of a good or service to the increase or decrease in its price. As a general rule, sales increase with drop in prices and decrease with rise in prices.
Typically, PeD has a negative value. For our purpose, in order to make it easier for our users, we will consider the absolute value of PeD. By default we setup PeD as 1 (unit elastic).
Optimal Price: the selling price where the company realize its maximum of profit.
Optimal Units: the number of selling units to be sold in order to realize the maximum of profit.
Total Variable Cost (VC): the cost that varies directly with the number of units produced or sold. Typical variable costs are: materials, packaging and shipping, sales commission, hourly wages, variable utilities (factory utilities) etc.
Total Variable Cost = Selling Units x Variable Cost per Unit
Total Cost (TC): total expenses incurred in the process of producing or selling a number of units.
Total Cost (TC) = Fixed Cost (FC) + Total Variable Cost (VC)
Total Revenue: the total sales value of the units produced or sold.
Total Revenue = Selling Units x Selling Price per Unit
Profit: the benefits from producing or selling a number of units.
                  Profit = Total Revenue – Total Cost

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