Problem-solving in life and in business can seem like a complex and intimidating effort causing many to fall back to a hands-off approach. But problems must be solved in a metalcasting operation or they eventually lead to additional costs to your business and loss of profitability.
Using structured problem solving, metalcasters take a systematic approach to identifying problems and finding a solution that addresses the problem’s root cause. This general strategy includes a focus on process metrics and customer needs.
Structured problem solving includes defining, describing and establishing possible causes; testing the most probable cause; verifying the true cause; and implementing well-tested countermeasures.
When integrated with existing records, such as shop floor incident reports, scrap reports, and customer feedback, quality assurance personnel can leverage proper questioning skills, critical and creative thinking skills, knowledge capturing skills, and diagnostic skills to solve incidents and problems efficiently and accurately.
Structured problem solving is effective because it provides focus in problem definition and consistency of direction in investigating the problem. It coordinates collection and analysis of data, facilitates communication between team members, management, and the customer, and promotes countermeasures that address the root cause and not its symptoms.
Costs of Quality
Quality is conforming to requirements at a cost the customer perceives as value. Four types of costs go into the total cost of quality: prevention costs, appraisal costs, internal failure costs, and external failure costs.
Prevention costs includes activities specifically designed to prevent poor quality, such as quality planning, internal system audits, training and supplier quality work. Appraisal costs are associated with measuring, evaluating, auditing products to ensure conformance to quality standards. Internal and external failure costs result from products not conforming to customer requirements, either occurring prior to or after shipment to the customer.
Most costs, especially those associated with external failures, are not obvious and can be difficult to quantify, such as lost customer loyalty, increased inventory, expediting costs, and late deliveries (Figure 1).
Problems cost more the further they occur from the process where they were made. This is because added value increases as more processing has been done on the product. The customer may be directly affected, and customer impacts are the responsibility of the supplier. Attendant costs, such as shipping, damage to equipment the casting was in, or labor costs, go up, as well.
Short-term corrective actions or poor solutions can sometimes add costs greater than the problem itself. Like a band-aid on a bad cut, it only lasts so long before the wound becomes worse and you have to pay for professional care.
Poor quality always has some cost. At a minimum, some level of prevention and appraisal is necessary, but those costs will be far less than failure.
The minimum cost is a significant dose of prevention, some appraisal costs and a minimal amount of internal failure. The implementation of preventive measures to control quality often takes a great deal of time and process knowledge. Appraisal measures are initially undertaken that cause internal failures to increase but external failures to decrease.
Quality maturity sees prevention costs increase and failure costs decrease. As problems are identified closer to the source of failure, fewer variables are at play, cause-and-effect relationships are better understood, and costs associated with correcting these failures decreases.
Prevention activities, especially quality planning, auditing, error proofing, and training, can yield a 10 to 1 return on investment according to the American Society for Quality’s Quality Cost Committee.
A good corrective action flow will start with problem communication and move to identifying and defining the problem (Figure 2). Once a problem arises, the personnel charged with solving it needs to write a clear and effective problem definition that details the issue the team wants to improve. It gives the primary metric, and if needed, a second metric, outlines the magnitude of the problem (usually with a financial impact) and sets the time frame. The problem definition should include a detailed, narrative description, be neutral to avoid jumping to solutions, and include a reference to a baseline measure. Table 1 lists sample problem definitions.
Every metalcasting facility has its own way of dealing with quality issues. Smaller facilities might only have a coordinator rather than a formal problem-solving team. But the coordinator and/or the team should involve quality assurance personnel for technical problem solving help, engineering/supervision for process help and implementation, maintenance for practical solutions, and operators for shop knowledge.
After defining the problem, the coordinator should move the team through isolation and containment, data collection and analysis, problem elimination or reduction, monitoring and documentation, and communication of the results of action. See the chart in Table 2 for information on each step.
To help in the problem identification, definition and information collecting process, simple forms can be used to communicate with the customer. A trouble report is a means of “listening” to a customer’s complaint. It may not give all the information you need, but the report can ask some simple questions to help you understand the problem and the customer describe the problem in meaningful terms. Sample questions can ask for specific descriptions of the problem, conditions under which it occurred, and the quantity affected. The form can also include information about customer expectations for correcting the problem.
Another useful form is a corrective action request for internal follow-up by quality, engineering, maintenance and operations personnel. These departments document what short-term actions they have taken to document and stop the problem from recurring, and give directions to others about the next steps required. This document also asks the problem be categorized so any further action, such as long-term measures or a root cause analysis, can be taken.
Quality alerts are documents issued to communicate the necessary short-term actions required by employees. It identifies the problem and shows key facts and should be posted where employees can access the information.
Short-term and long-term measures can be used to solve a problem. Short-term actions may include:
Quarantine of suspect parts.
Extra sampling and testing.
Extra inspection, including lot control for scrap or rework.
Establishing acceptable (temporary) rework or salvage procedures, if possible.
A critical element in short-term action is communication with the customer so they know they are protected. Customers are key stakeholders, and they hate being in the dark when there’s an issue, whether quality or delivery.
It’s important to make the distinction between acute and chronic problems. Chronic problems exist when performance is below standard but relatively stable over a long period of time. It is often related to the basic capability of the process, and fixing it requires fundamental process improvement. An example of a chronic problem is overall equipment efficiency of 65% over the past two years, which is below a target of 75%.
An acute problem exists when performance worsens significantly from the normal level. This can be over a very short period of time or be sporadic and is often related to some undocumented deviation in the process. An example of an acute problem is three field failures in the last three months after five years with zero failures.
The full application of a program like Six Sigma is probably not appropriate for acute problems even when the root cause is a system issue. If there is a flaw at the system level, it doesn’t necessarily involve a fundamental change to the process except at a management level.
While short-term measures only address the immediate problem, to keep customers happy, sometimes these measures are necessary to do what’s right for them and to meet contractual obligations. If short-term measures are required repetitively, however, you haven’t addressed the root cause or “real problem.”
Long-term countermeasures are not necessarily complex or facility-wide, but they permanently alter the system of doing things. They address the root cause. Typically, long-term measures will involve a documented alteration of the process.
Tips for success in long-term measures include:
Take control of the problem-solving process and get management’s buy-in.
Have a standard response format in place for external customer complaints.
Get started on the corrective action as soon as you have a reasonable idea of the problem. Don’t wait for perfect information.
Too frequent corrective action cycling overwhelms management systems. Don’t issue unneeded CAR’s.
Tailor your effort to the true impact of the problem.
Don’t leave problem solving to the quality department. Practical input from the plant floor, supported by data, is essential in developing effective countermeasures.
During the problem-solving process, have a communication plan to keep team members, customers, and management informed:
Appropriate information and level of detail (edit carefully!)
Preferred medium (e.g. emails, phone calls, meetings, one-on-ones, reports) for each stakeholder.
Appropriate frequency of communication.
Be pro-active! Ask stakeholders how they want to be kept in the loop.
After a problem is solved, ask, “What have we learned?”
Correlating data and positive customer feedback and positive feedback from those internally working to solve the problem will be indicators your corrective action measures are working. n
This article is based on a small portion of the AFS Institute classroom course, Foundry Process Improvement.