Key Process Input Output Variable Definition

Cite this article as:"Key Process Input Output Variable Definition," in The Business Professor, updated March 22, 2019, last accessed October 21, 2020,


Key Process Input or Output variable (KPIV)

Key process input or output variable (KPIV) refers to various factors that can cause an impact during a process or journey. Once the key process input variables for a process are determined, statistical experiments can be designed that can reveal optimal values for each factor to be achieve desired output quality.

A Little More on What is a Key Process Input or Output Variable

Factors within a process correlated to output characteristics(s) are important to the internal or external customer. Optimizing and controlling these is vital to the improvement of the KPOV. A good example is income variability, income is an independent variable because it causes and influences another variable consumption.  Income (KPIV) will determine the quality of a commodity bought or the service given out which is the (KPOV).

We can also have another example of a company that looks to increase profit margins on t-shirts by using a cheaper fabric supplier, would evaluate the project’s success depending on whether customers continued to buy them, or if sales decreased due to poor satisfaction. The end-goal profit margins, number of sales, and customer complaints are examples of output variables (KPOV), whereas the decision to change suppliers is an example of the input variable (KPIV).

The main point here is finding the good KPIV that will lead to a significant production of KPOVs in a system or in a company. Therefore, Design of experiments (DOE) can be used to find out the impacts of KPIV and KPOV co-relation in the final results of certain changes of variables in a system or a process.

Examples of KPIV:

  • ¬†¬†¬†¬†¬†¬†¬†¬†The type of fabric
  • ¬†¬†¬†¬†¬†¬†¬†¬†The quality of the fabric
  • ¬†¬†¬†¬†¬†¬†¬†¬†The price if the fabric
  • ¬†¬†¬†¬†¬†¬†¬†¬†The cost of making the t-shirts

References for Key Process Input Variable

Academic Research on Key Process Input or Output variable (KPIV)

  • Application of Six Sigma methodology for process design, Sokovic, M., Pavletic, D., & Fakin, S. (2005). Journal of Materials Processing Technology, 162, 777-783. This article looks at the six stigma modeling techniques; it is possible to build up a picture of the various inputs and outputs of a process. Six Sigma methodology follows a rigid roadmap for process improvement and problem-solving, which focuses on the stages of DMAIC (define-measure- analyze-improve-control).
  • Optimizing order fulfillment using design for six sigma and fuzzy logic, Amer, Y., Luong, L., Lee, S. H., & Ashraf, M. A. (2008). International Journal of Management Science and Engineering Management, 3(2), 83-99. KPOVs are usually identified by mapping out business processes, usually using the SIPOC (supplier, input, process, output, and customer) method. ¬†By identifying these simple variables, you can develop a richer picture of how your business process interacts. Supply chain handling in a business process and customer satisfaction is now the major issues. The supply chain includes the processing of the goods from raw materials, to its packaging and transportation as finished goods to the customer. During this chain supply process, the different challenge may be encountered including, breakage of goods, some goods may be stolen and product delays. Trough application of the six stigma design then the customer‚Äôs needs and wants can be easily met. Proper handling of chain supply, including the application of transfer theory to predict the presence of the stock order leads to proper chain supply performance
  • Application of Six-Sigma DMAIC methodology to sand-casting process with response surface methodology, Kumaravadivel, A., & Natarajan, U. (2013). The International Journal of Advanced Manufacturing Technology, 69(5-8), 1403-1420. In this article we also look at the flywheel casting process in where the six stigma processes where applied to determine the shortcomings in the process. The cause-and-effect matrix, process map, and the failure mode effects analysis were used. ¬†This experiment was used to find out the impacts of each and every component used in the component which includes; water quantity, water porosity, chlorophyll effect and blast off on sand grounding. Respond surface methodology (RSM) was used in interpreting the findings. Depending on the results, the parameters used in the study were also used in another experiment and better results were obtained. ¬†The two findings from the two experiments, that is the tried process and the proposed experiment have been explained more in this article.
  • Measure for six sigma success, Pearson, T. A. (2001). Quality Progress, 34(2), 35. The author in this article is concerned with measures that can be utilized for the success of the sigma.
  • An overview of six sigma, Montgomery, D. C., & Woodall, W. H. (2008). International Statistical Review, 76(3), 329-346. This article is focused on dwelling on an overview of the six sigma. The author uses a number of aspects to look into the various aspects of a number of sigmas.
  • Reducing mold changing time by implementing Lean Six Sigma, Lee, K. L., & Wei, C. C. (2010). Quality and Reliability Engineering International, 26(4), 387-395. Six stigma methodology aims at the production of good quality services, goods, and services while reducing deviations and measuring defects. Lean production is a strategy that aims to increase the processing speed of goods and supply including the reduction of the spoilage of goods in the process. ¬†Incorporation of the two processes together, that is the six sigma and lean strategies give out better results that neither the system can achieve solely. A case study was conducted at the printed circuit Board Company in China showing how the company used the Lean Six Sigma project successfully. The in-circuit experiment was conducted on the shape type, the model of the circuits used in the making process. Discoveries and improvement strategies are being brought up to maintain and boost the competence of the mold shifting procedure.
  • Application of Six Sigma methodology for process design quality improvement, Sokovic, M., Pavletic, D., & Fakin, S. (2005). In 13th Scientific International Conference ‚ÄěAchievements in Mechanical and Materials Engineering, AMME (pp. 611-614). This case shows the use of six sigma strategy in the course plan. Compressor-housing machining process design and development at the Cimos facility in Buzet is used as an example for the usage of some Six sigma apparatus put in work. ¬†Process map and the cause and effect matrix were used majorly. A customized strategy with the main six sigma tools included is shown and contrast of the old strategies is done and the findings are explained.
  • Using Six Sigma to improve replenishment process in a direct selling company, Wei, C. C., Sheen, G. J., Tai, C. T., & Lee, K. L. (2010). Supply Chain Management: An International Journal, 15(1), 3-9. The main purpose of this article is to recommend the usage of the Six Sigma methodology to ensure progressive replacement procedure in the logistic center of Amway Taiwan Company. In this study, the six sigma strategies are used which include; define, measure, analyze, improve and control (DMAIC) strategy is used, including the dependent and independent variables. Controlled strategies are made to maintain and improve the change procedure. Six Sigma system can be implemented by the logistic hubs of other direct companies. ¬†Conversely, they can amend these tools to fit their companies setting. This article shows a plan in which six sigma methodology is used to better the changing development of Amway Taiwan logistic hub. It shows how this methodology was put in action according to different stages and how the system progression was obtained. In summary, this project stresses the positive impacts of using the six sigma system. ¬†This article can be of great use to people who head practical research projects and to intellectuals. Six Sigma system included logistic strategies was used in a direct sales company. Other companies which may be interested or may like to use the Six Sigma methodology can look up to the positive impacts that were achieved in the Amway Taiwan logistic hub project.
  • A methodological comparison of three strategies for quality improvement, De Mast, J. (2004). International Journal of Quality & Reliability Management, 21(2), 198-213. Few strategies are projected in context for excellent project development. Juran defines quality improvement as a logical search/hunt of development opportunities in manufacturing ways. These strategies include the Shainin, the Taguchi‚Äôs and the Six Sigma system. ¬†These two strategies are compared according to the outline strategy for excellent development. The weaknesses and strengths of each of these strategies are pointed out. The six sigma methodology is the best strategy of the three since the Shainin structure only looks out at the recognition of the main origin of a problem while both the Taguchi’s system and the Six Sigma plan utilizes the arithmetical modeling system.
  • Disentangling causal relationships of a manufacturing process using genetic algorithms and six-sigma techniques, Johnston, A. B., Maguire, L. P., & Mcginnity, T. M. (2008). International Journal of Production Research, 46(22), 6251-6268. ¬†Compact disk manufacturing companies face a great challenge of the competition due to advancement in expert knowledge. This has then forced the manufacturing companies to come up with ways of controlling the benefits of making the CD over the competitors. This article, therefore, looks in ways of upgrading business with smart strategies for enhancement of the manufacturing competence. A case study was conducted to show the fundamental relations in the making of the CD drives apparatus. This article shows the application of smart strategies to help in the execution of business upgrade ways within the working area. ¬†Major benefits can be achieved by using these thoughtful moves. This strategy is proven by the end results which helped the manufacturers to make desired disks and also looking on at minor things that down looked the use of the Six-Sigma plan.
  • Six Sigma principles in marketing: an application, Das, N., Gauri, S. K., & Das, P. (2006). Six International Journal of Six Sigma and Competitive Advantage, 2(3), 243-262. ¬†Every company or business sitting has different marketing strategies, which plays a big part in its expansion and development. ¬†Putting in use the Six Sigma strategies to the marketing of companies or business can enhance honest decision-making skills which leads to the satisfactory end product or customer contentment. In this article, different issues have been pointed out, which include proper chain supply of fresh goods to clients in the whole sell shops by maintaining a good flow of goods from the stock room to the whole sell shops which can only be achieved by maintaining marketing rules, in an Indian company. ¬†Shortcomings of the use of the Six Sigma tools are identified and goals are set on the upgrade of the action plan. Positive impacts of the application of the DMAIC strategies were noticed and measured in terms of market levels of the firm and the sigma point of view. Better results of this plan can also be well thought out in the upgrade of goods produced, declined operation cost in a company and improved client maintenance.

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