Download - Wk 1 - Overview of SPC
OVERVIEW OF SPCBPT 2423 – STATISTICAL PROCESS CONTROL
Customer
Supplier
Order
Demand Forecast
Prod. Plan Control
Inventory Control
Purchase Order
Manufacturing
Planned Maintenance
Industrial Engineering
Quality Management
Finance & Management
Business Dev. & Marketing
Manufacturing Process Flow
INTRODUCTION
Delivery Quality Customer Satisfaction
Buying Products
Produced by a process that is stable or
repeatable
Process must be capable of operating with little variability around the target or nominal
dimensions of the product’s quality characteristics
USE OF SPC IN QUALITY SPC is most effective when it is integrated into an overall
companywide quality improvement program To improve quality and productivity – start with managing
facts and data and not simply rely on judgment
Processes do not naturally operate in an in-control state
Use of control
charts in an SPC program
To eliminate assignable causes,
reduce process variability and
stabilize process performance
Example of Products
USE OF SPC IN QUALITY
Products
Process Control
Process Flow
Process Data
USE OF SPC IN QUALITYChance and Assignable Causes Chance / Common Causes
small random changes in the process that cannot be avoided – due to the inherent variation present in all processes
only removable by making a change in the existing process – involves management intervention
Example : temperature in the factory building
Assignable Causes variations in the process that can be identified as having a
specific cause (causes that are not part of the process on a regular basis)
variation arises because of specific circumstances Example : changes in the thickness of incoming raw
material, broken tool Source of variation : process itself, the material used, the
operator’s actions or the environment
USE OF SPC IN QUALITY Elements of a Successful SPC Program
1. Management leadership2. A team approach, focusing on project-oriented
applications3. Education of employees at all levels4. Emphasis on reducing variability5. Measuring success in quantitative (economic)
terms6. A mechanism for communicating successful
results throughout the organization
APPLICATION OF SPC
Define
Opportunity
•Identify and/or validate the business
•Define critical customer requirements
•Establish project charter, build team and document (map) processes
Measure
Performance
•Determine what to measure and sigma performance level
•Manage measurement data collection
•Develop and validate measurement systems
Analyze Opportunity
•Analyze data to understand reasons for variation and identify potential root causes
•Determine process capability, throughput, cycle time
•Formulate investigate and verify root cause hypotheses
Improve
Performance
•Generate and quantify potential solutions
•Evaluate and select final solution
•Verify and gain approval for final solution
Control Performance
•Develop ongoing process management plans and find mistake-proof process
•Monitor and control critical process characteristics
•Develop out of control action plans
APPLICATION OF SPC
Statistical Process Control
Manufacturing Nonmanufacturing / Service Businesses
APPLICATION OF SPC Service industry applications of SPC and related
methodology sometimes require ingenuity beyond that normally required for the more typical manufacturing applications.
Two primary reasons for this difference :1. Most service businesses do not have a natural
measurement system that allows the analyst to easily define quality
2. The system that is to be improved is usually fairly obvious in a manufacturing setting, whereas the observability of the process in a nonmanufacturing setting may be fairly low
Key to applying SPC in a nonmanufaturing environment is to focus initial efforts on resolving these two issues.