QUALITY IMPROVEMENT METHODOLOGIES FOR CONTINUOUS IMPROVEMENT OF PRODUCTION PROCESSES AND PRODUCT QUALITY AND THEIR EVOLUTION
Abstract:
In order to be competitive companies try continuously improve their production processes, product quality and increase the level of customer satisfaction by implementing different quality improvement programs, methodologies and approaches. Nowadays there are different worldwide used methodologies like PDAC, 8D, Six Sigma DMAIC, 4Q which enables the companies to select and combine them for continuous improvement. In this paper will be introduced the general idea of using these methodologies, it will be followed by discussion where will be made the comparative analysis that will clarify their advantages and disadvantages and shows in what case the appropriate methodology could be selected.
Key words: PDCA, 8D, DMAIC, 4Q
1. INTRODUCTION
Today customer satisfaction is the feeling of pleasure that occurs when a company meets a customer’s expectations. Gaining high levels of customer satisfaction is very important to a business because satisfied customers are most likely to be loyal and to make repeat orders and to use a wide range of services [
1, 2]. A company that succeeds on meeting and exceeding customers’ expectations is guaranteed to have great Return On Investment (ROI) [3, 4]. Today the reliable and stable production processes influence on a lot of KPI that are very important for business success. In addition, metrics can provide managers with information about problematic points and show the real status of enterprise at certain time [5]. For instance the more reliable and stable production processes is the less scrap occurs, and less rework is needed, which consumes additional recourses, time and money [6]. Therefore, in order to be competitive and successful on the market place and satisfy customer, companies should continuously improve their production processes and product quality by implementing different quality improvement programs and methodologies [7]. A quality improvement effort will lead to a higher product and service quality that will lead to improved customer satisfaction [8]. In this paper will be reviewed and discussed four different quality and process improvement methodologies which are intended to solve customer complaints and problems in virtual organisation network [9, 10]. Presented findings are intended to be used as information for management decisions about what quality improvement methodology should be selected for continuous improvement in Partner Network enterprises. Figure 1 shows related research papers but in this paper will be presented the third part.
Fig. 1. Related research papers
2. LITERATURE REVIEW
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2.1. Plan Do Check Act (PDCA)
| In 1939 Walter Shewhart displayed the first version of the scientific method with his cycle "Shewhart Cycle": Specification, Production, Inspection [11]. In 1950, Deming modified the Shewhart cycle at a Japanese Union of Scientists and Engineers (JUSE). His straight line: Design, Produce, Sell was converted to a circle with a forth added step - Redesign through marketing research [12]. In 1950 at JUSE seminar Imai recast the Deming wheel into the Plan, Do, Check, Act (PDCA) cycle and presented the correlation between the Deming wheel and the PDCA cycle shown in Table 1 [13]. Design - Plan |
Product design corresponds to the planning phase (definition of a problem and a hypothesis about possible causes and solutions) |
|
Production - Do |
Production corresponds to doing-making, or working on the product that was designed (implementing) |
|
Sales - Check |
Sales figures confirm whether the customer is satisfied (evaluating the results) |
|
Research -Action |
In case of a complaint being filed, it has to be incorporated into the planning phase and action taken for the next round of efforts ack to plan if the results are unsatisfactory) |
2.3. Six Sigma DMAIC
Dating back to the mid of 1980s, applications of the Six Sigma methods enabled many organizations to sustain their competitiveness by integrating their knowledge of the process with statistics, engineering and project management [
19]. Motorola was the first company who launched a Six Sigma project in the mid-1980s [20]. Initially Six Sigma was applied in manufacturing [21] but today it is accepted in healthcare [22], finance [23] and service [24]. Six Sigma is a project-driven management approach intended to improve products, services and processes by reducing defects [25]. It is a business strategy that focuses on improving customer requirements, business systems, productivity and financial performance. Utilizing analytical tools to measure quality and eliminate variances in processes allows to producing near perfect products and services that will satisfy customers [26]. Below is present Six Sigma’s DMAIC description.
Define step is where a problem is identified and quantified in terms of the perceived result. The product and/or process to be improved are identified, resources for the improvement project are
put in place and expectations for the improvement project are set.
Measure step enables to understand the present condition of its work process before it attempts to identify where they can be improved. The critical to-quality characteristics are defined and the defects in the process/product developed through graphical analysis. All potential effects on failure modes are identified.
Analyse step adds statistical strength to problem analysis, identifies a problem´s root cause and determines how much of the total variation is.
Improve step aims to develop, select and implement the best solutions with controlled risks. The effect of the solutions that are then measured with the KPI developed during the Measure step.
Control step is intended to design and implement a change based on the results made the Improve step. This step involves monitoring the process to ensure it works according to the implemented changes, capture the estimated improvements and sustain performance [26].
2.4. 4 Quadrants (4Q)
