Author : M.Temel AYGUN
Starting the project & defining added value
Before the start of the project, the product or product family is determined, which is going to be analyzed. A product family is a group of products that occupies the same or similar resources in production and order processing. The VSA 4.0 is carried out for the entire order processing process. Therefore, the project team must also be assembled cross-departmentally. Employees from marketing, sales and adjustment development should especially be integrated.
At the beginning it should be clarified which product characteristics are especially important for customers and how they are created today. This helps refine one’s awareness for non-value-adding activities in the VSA. At the same time it is to define, what the value stream has to accomplish in the future in order to establish a striving competitive advantage (e.g. “…we deliver faster than…”, “…free product configuration…”) and to realize the planned business model. Then a clear target should be set by management which KPIs should be improved for the selected product group (e.g. reduce order throughput time to X days, reduce First Time Failure Rate to Y ppm, etc.) to achieve the desired competitive advantage. This makes it easier for the project team to prioritize improvement opportunities. In this way, improvement ideas can already be thought up by the team during the analysis phase to shape the future state vision.
Analyze the current state – Value Stream Analysis 4.0
The traditional VSA initially creates an overarching understanding of the value stream for all involved. The result is a value stream representation with visualized areas of potential, the Kaizen flashes. The familiar process boxes from the VSA are first extended upon in the VSA 4.0 in such a way that the collected information sources can be represented in extended notation. The type of data collection is characterized by the collection interval and its type of recording. At the same time, the respective current value is determined and inscribed in the process box. This notation should be used as uniformly as possible across all processes.
Understanding and incorporating storage media for information
To make the handling of data and information transparent, horizontal lines for each used storage medium are now delineated on the value stream map below the process boxes. Examples of storage media are paper, ERP systems, MES or MS Excel®, as well as the employees themselves. Next step is the analysis and representation of the information flows from the sources to the storage media. Therefore, information sources are affiliated with the associated storage media through vertical lines and nodal points.
Analyzing the use of information
Subsequently, there is a review of which applications the collected information is used for, e.g. in quality management, for order control, or for shop floor management. For every type of usage, just like for storage media, horizontal lines are inscribed. Information sources, in turn, are subsequently affiliated with the applications through vertical (in this case, dashed) lines and points. Here it already becomes evident as to which collected information will not be used or will be used differently than intended.
Recording wastes in information logistics In this step, the already introduced wastes in information logistics are recorded for all processes and inscribed as Kaizen flashes. Furthermore, the observed level of waste in dealing with information can be quantified by means of figures. As an example, here three figures are specified:
- Data availability: It answers the question what percentage of necessary information/figures is actually being recorded.
- Data usage: It shows what percentage of the recorded information sources is actually subsequently used.
- Digitalization rate: It discloses what percentage of the recorded information sources is digitally recorded.
These figures can be calculated for a single workstation, a line or the entire order throughput.
Example application of VSA 4.0
The example shows a portion of the value stream of a special machine manufacturer, which extends from customer contact all the way to production (Fig. 17). Though products are individually adjusted in size and material depending on the customer’s application the order-specific information processing (customer clarification, adaptation of drawing, CNC programming) is basically the same for every customer project. The programming time for an order amounts to approx. 30 minutes and ultimately represents an implementation of the customer’s desired product parameters in a CNC code.
The following wastes arise from the traditional value stream analysis:
- Frequent questions from construction to sales
- Machine downtime during programming
- Rejects due to programming errors
The application of VSA 4.0 provides further insights:
- To exchange data and information, twelve different storage media are necessary (number of horizontal lines).
- The high number of nodal points on the vertical lines of the data exchange indicates that process steps use several storage media for the same information.
Additional wastes arise from this, e.g.:
- Employees must transmit information from different systems and with different formats by hand.
- Media disruptions hinder the smooth flow of information and extend the processing time.
The figures confirm the findings and demonstrate additional potential for improvement:
- The data availability of the key performance indicators desired by management, such as processing time, quantity, etc. is 0 % for all processes.
- None of the recorded information is being used in order to push forward an improvement of the value stream (undermost horizontal line). The data usage figure is therefore 0 %.
- The digitalization rate in the value stream is 0 %, since paper is the storage medium used in different forms for every exchange of information.
Quick order processing through the synchronization of information flows
The traditional VSD aims to reduce the throughput time of a product by eliminating non-valueadding activities. Information is considered mainly from the process control perspective. This doesn’t sufficiently take into account the comprehensive, new opportunities for the use of information through digitalization and networking. Companies in mechanical engineering must consider further information flows beside the information for process control in order to be able to supply customers quickly and flexibly, improve processes, and increase the customer value through information-based services. Four information flows can be recognized that must mesh together in synchronization:
The product flow represents the physical flow of material. In production, this coincides with the product information flow (see below), partly from the flow of suppliers.
The utilities flow controls the provision and transport of necessary operating and auxiliary materials for the execution of an order.
The process information flow comprises information about the condition of production and all supporting processes (like processing time, force, temperature, pressure, etc.).
The product information flow comprises all information about the product. It begins with the customer but leads through development (e.g. drafting of drawing) and work preparation (e.g. programs, work plans) all the way to logistics, production and to the customer.
If one of the four information flows comes to a halt or is not synchronized with the other flows, delays can result due to waiting times. In order to avoid this, a synchronization of these information flows should be ensured. This is especially demanding in production, as all four flows encounter one another here. At a workstation, the work and testing instructions must be available at the same time as the physical product, the tools, fixtures and measurement devices, and the necessary process parameters configured. In addition, the customer is to be linked to the in-house information flows in order to accelerate order clarification, adaptation development and work preparation, but also to receive product information from the usage phase.
See you in next blog with the following topics :
- Determining the target condition – Value Stream Design 4.0
- Digitally improving product flow
- The new process in detail
Kadıköy, İstanbul – TURKEY
M. Temel AYGÜN, Ph. D. in Aerospace Eng.
Copyright belongs to Author.