3 FUNDAMENTALS OF VALUE STREAM METHOD

The central objective of value stream mapping is the identification and elimination of waste in each connected process. Using this method to document value add processes, redundant procedures and operations waste is thereby also documented. From the adopted customer perspective, value added should be created as parts will be produced to customer specifications with as little waste (muda) as possible. In this respect every process in the value stream needs to be connected in such a way as to produce a production flow with optimum stocks, minimum cycle time and low defect and scrap rates. This method’s optimization areas therefore consist of shortening cycle times, increasing production and reducing stock levels [3]

[4].

3.1 Value stream operating principles

In contrast to examining the company layout, in which important information such as information flow and upstream or downstream process chains are not visible, value stream mapping describes the essential company procedures using simplified symbols. A concise representation of the company’s business processes with regard to production, material and information flow is thus achieved. Not least due to the simplicity of use, has the value stream method been identified as a valued analysis and design tool. The application of this method requires solely the use of pencil, eraser and paper. Furthermore, through the designation of a value stream manager, competencies and responsibilities are combined. The manager also ensures that the individual sub-projects can be responsibly realized [3]

[4].

In summary, it can be said that the value stream mapping is an integrated analysis, communication and design tool, which in manufacturing begins with the arrival of raw material in the warehouse, ends at dispatch and can be extended to cover all upstream and downstream processes (suppliers and customers). In this connection material and information flow is examined and this extends into administrative areas.[4]. Fig. 1 shows a typical value stream map.

Comparison of Companies in Terms of the Applicability of Value‐Stream‐Design

Figure 1: Value stream map example.

3.2 Value stream mapping targets

The aim of manufacturing optimization is to increase efficiency, with easy to implement measures; for this purpose, it is necessary to determine the company’s current state, in order to enable appropriate target achievement rates [4]. In fig. 2 appropriate targets have been identified from relevant literature, which will be pursued using value stream mapping.

Target dimensions Economy, Variability, Speed, Quality Attain ideal vision of flow with high value add Implement and improve production processes

Establish value Stream optimized factory through use of design guidelines Introduce Lean principles

Reduce lead time Reduce inventory Improve quality Increase productivity

Recognize and eliminate waste and weaknesses (Kaizen) Recognize Holistic/ Integrated flow

Create corporate communication platform Create basis for discussion / decision

Creation of transparency through symbolism / process abstraction Depict connection between material and information flow Secondary Targets

Process optimization targets can be put into operation and target values can be formulated based on strategic direction. The main target dimensions have been classified into a general target system. Using the value stream method specific targets are also created, which are presented as secondary objectives arising from the use of this technique and illustrate the unique selling points of value stream mapping. Finally, target achievement rates enable the graphical representation of value stream mapping results, which is considered in the impact model [4] [5].

3.3 Value stream technique classification

At the heart of this value stream diagram is a product family, which is placed in the center of the diagram and is of direct relevance to a customer or customers. This results in an integrated customer-oriented perspective (process oriented) within defined system boundaries.

The scope of the boundaries in classic value stream mapping that can be linked to two typical models occurs on three levels:

 Plant / Factory

 Production

 Workplace / Machines

Through this, illustration of the analysis scope and design and, therefore, the way value stream mapping works is made possible.

The connection between the influence of value stream hierarchy and process on a company or production level is clearly demonstrated (Fig. 3).

Customer

Figure 3: Comparison of process model and hierarchy model.

Based upon the manufacturing company’s vertical levels in the hierarchy (depth) model, the value stream technique affects all production levels. No impact is made upon corporate leadership. Production, factory and

Comparison of Companies in Terms of the Applicability of Value‐Stream‐Design

administration areas are well documented [6]. The horizontal (width) process model illustrates recording of company processes as well as support processes. Management processes remain unaffected.

3.4 Value stream method scope parameters

Based upon these results, the spectrum of the scope of value stream techniques can be illustrated, which in the vertical ‘level of detail’ as well as in the acquisition of all relevant figures, data and facts can be illustrated through the ‘information content’. The ‘scope boundaries’ are to be determined in advance. Both scope directions have a significant influence upon the ‘effort’ required for the analysis. The ‘complexity’ of a production area should be reduced using VSM into a describable and manageable format. For this purpose, VSM is subject to the use of classifications and symbols, which can be illustrated by adherence to ‘standardization’. With respect to optimization of current business processes, employees must be included in the process in order to achieve high acceptance of the results and ‘transferability’ to further product families. These team-oriented aspects take place in VSM by involving the employees closely in the analysis and design process, which is to be taken into account when committing personnel resources to the VSM [7] [8] [9].

The scope should be identified at the start of the process and will be referred to as scope parameters below. Fig. 4 combines the value stream method scope parameters and illustrates the abstraction range of company processes. These scope parameters will be integrated into the impact model in order to display them from the start.

Level of detail