Quality control
SKRIV DETTE ABSTRACT OM NÅR DU ER DONE
When managing conformance in construction projects an important aspect is quality control (QC), in order to assure high quality of outcome as well as in the project process. Thus the main purpose of performing QC is to determine if the established quality requirements and the project objectives are achieved. Furthermore an important part of QC is to investigate the causes of the arising problems, as well as finding ways to eliminate unsatisfactory performance.
As quality control techniques are needed in order to perform QC, two quality control techniques are introduced in this article. The first technique introduced is “cause and effect diagrams”, which focus on correcting the non-conformance after it has occurred, which is the focus of most quality control techniques. The idea of the technique is to find the roots to the problem and visualizing them by creating a fish bone diagram. The possibilities and limitations to the technique will be clarified. “Statistical process control” is a tool to prevent unsatisfactory performance and is the second technique introduced in the article. This technique deals with statistical analysis of data obtained from similar projects, and control chart can be used to determine if the outcome of the analysis is tolerable. As this technique requires data logging of previous projects, the possibility of implementation of the technique in a construction process is discussed as the complexity and conformance requirements in construction projects can make the technique less effective even though the construction process is a repetitive process overall.
Contents |
Definitions of quality control
Quality Control (QC) is a part of quality management of construction projects and the aim is to assure high quality of the project process and of the construction being built. Quality Control is at the heart of conformance management and in this content the definition of “high quality” means fulfilling standards and the established quality requirements in the specific project. Thus the development process and design output have to meet the input requirements, where the primary inputs and outputs of quality control is given by the ISO 21500:2013 are shown in Table XX. WRITE MORE TO THIS TABLE!!!
Primary inputs | Primary outputs |
---|---|
Progress data Deliverables Quality plan |
Quality control measurements Verified deliverables Inspection reports Change requests Corretive actions |
The ISO 21500:2013 (standard??) states that QC should be performed during the whole project life cycle and that it includes following aspects:
- Monitoring the quality of the processes and outcome.
- Analysis of the causes of non-conformance.
- Identify ways to eliminate unsatisfactory performance.
- Communication of the changes requests and necessary corrective actions.
Karins definition: (Den store report)
John S. Oakland states:
Something about recent practice (digital tools for inspections) and classic quality control techniques... The focus on predictive quality control!!!
Product quality control
Process quality control
Performing quality control
Continuous control, Early quality control, Quality control at delivery
Monitoring
Manual inspections
Quality control of own work - Identifying the non-conformance early
Digital tools for inspections
Sensor systems
Radio Frequency Identification (RFID)-based quality management system, which functions as a platform for gathering, filtering, managing, monitoring and sharing quality data.
Quality control techniques
Corrective techniques
Most techniques focus on correction of non-conformance
Cause and effect diagrams
Pareto analysis
Control charts
Preventive techniques
Statistical process control
Implementation of preventive techniques
Discussion
What is good quality control
Benefits of good quality control
Consequences of poor quality control
Limitations
The requirements have to be clear
Project specific control
Time – there have to be time to do it.
Knowledge – people have to understand the process in order to control them.