Compared to value chain, the value stream is a far more focused and contingent view of the value-adding process that tries to highlight wastes as identified by Ohno.
The Seven Value Stream Mapping Tools
Peter Hines and Nick Rich
Lean Enterprise Research Centre, Cardiff Business School, Cardiff, UK
International Journal of Operations & Production Management, Vol. 17, No. 1, 1997, pp. 46-64.
Seven Value Stream Mapping Tools
Process activity mapping
Supply chain response matrix
Production variety funnel
Quality filter mapping
Demand amplification mapping
Decision point analysis
Physical structure
Mapping tool Origin of mapping tool
(1) Process activity mapping Industrial engineering
(2) Supply chain response matrix Time compression/logistics
(3) Production variety funnel Operations management
(4) Quality filter mapping New tool
(5) Demand amplification mapping Systems dynamics
(6) Decision point analysis Efficient consumer response/logistics
(7) Physical structure mapping New tool
The Seven Tools - Brief Explanation
(1) Process activity mapping - Industrial engineering
Industrial engineering comprises a group of techniques that can be used to eliminate from the workplace waste, inconsistencies and irrationalities, and provide high-quality goods and services easily, quickly and inexpensively. The technique is known by a number of names in this context, although process analysis is the most common.
There are five stages to this general approach:
(1) the study of the flow of processes (Operations of the process);
(2) a consideration of whether everything that is being done at each stage (operation) is really necessary and what would happen if superfluous tasks were removed (the identification of waste operations);.
(3) a consideration of whether the process can be rearranged in a more efficient sequence;
(4) a consideration of a better flow pattern, involving different flow layout or transport routing.
The process is categorized in terms of a variety of activity types (operation, transport, inspection and storage). The machine or area used for each of these activities is recorded, together with the distance
moved, time taken and number of people involved. A simple flow chart of the types of activity being undertaken at any one time can then be made.
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Next the total distance moved, time taken and people involved can be calculated and recorded. The completed diagram can then be used as the basis for further analysis and subsequent improvement. Often this is achieved through the use of techniques such as the 5W1H (asking: Why does an activity occur? Who does it? On which machine? Where? When? and How?). The basis of this approach is therefore to try to eliminate activities that are unnecessary, simplify others, combine yet others and seek sequence changes that will reduce waste. Various contingent improvement approaches can be mapped (more detailed maps) before the best approach is selected for implementation.
(2) Supply chain response matrix - Time compression/logistics
The origin of the second tool is the time compression and logistics movement and goes under a variety of names. Beesley[4] applied what he termed “time-based process mapping” to a range of industrial
sectors including automotive, aerospace and construction.
This mapping approach, seeks to portray in a simple diagram the critical lead-time constraints for a particular process. In this case it is the cumulative lead time in a distribution company, its suppliers and its downstream retailer. In Figure the horizontal measurements show the lead time for the product both internally and externally. The vertical plot shows the average amount of standing inventory (in days) at specific points in the supply chain. Each of the individual lead times and inventory amounts can be targeted for improvement activity.
(3) Production variety funnel - Operations management
This approach originates in the operations management area. IVAT analysis views internal
operations in companies as consisting of activities that conform to I, V, A or T shapes:
• “I” plants consist of unidirectional, unvarying production of multiple identical items such as a chemical plant.
• “V” plants consist of a limited number of raw materials processed into a wide variety of finished products in a generally diverging pattern. “V” plants are typical in textiles and metal fabrication industries.
• “A” plants, in contrast, have many raw materials and a limited range of finished products with different streams of raw materials using different facilities; such plants are typical in the aerospace industry or in other major assembly industries.
• “T” plants have a wide combination of products from a restricted number of components made into semi-processed parts held ready for a wide range of customer-demanded final versions; this type of site is typical in the electronics and household appliance industries.
Such a categorization of the production system using the production variety funnel allows the
mapper to understand how the firm or the supply chain operates and the accompanying complexity that has to be managed. In addition, such a mapping process helps executives to understand the similarities and differences between their industry and another that may have been more widely researched.
(4) Quality filter mapping - New tool
The quality filter mapping approach is a new tool designed to identify where quality problems exist in the supply chain. Three different types of quality defect occur in the supply chain.
(1) The first of these is the product defect. Product defects are defined here as defects in goods produced that are not caught by in-line or end-of-line inspections and are therefore passed on to customers.
(2) Service defects are problems given to a customer in the area of service accompanying the goods. The most important of these service defects are inappropriate delivery (late or early), or incorrect
paper work or documentation. In other words, such defects include any problems that customers experiences not involving production faults.
(3) Internal scrap refers to defects produced in a company that have been caught by in-line or end-of-line inspection.
Each of these three types of defect are then mapped latitudinally along the supply chain. At each supply chain step, the number of defects of each category are recorded. This approach helps in identifying where defects are occurring and hence in identifying problems, inefficiencies and wasted effort. This information can then be used for subsequent improvement activity.
(5) Demand amplification mapping - Systems dynamics
Demand amplification mapping has its roots in the systems dynamics work of Forrester and Burbidge.
“Forrester effect” was first described in a Harvard Business Review article in 1958 by Forrester. This effect is linked primarily to delays and poor decision making concerning information and material flow.
The Burbidge effect is linked to the “law of industrial dynamics” which states:
if demand is transmitted along a series of inventories using stock control ordering, then the amplification of demand variation will increase with each transfer.
As a result, in unmodified supply chains generally excess inventory, production, labour and capacity are found. Still stockouts occur. In a supply chain setting, manufacturers therefore have sought to hold – in some cases sizeable – stocks to avoid such problems.
In a simple example of this type of mapping two curves are plotted. The first, in the lighter shading, represents the actual consumer sales as recorded by electronic point-of-sale data. The second, and
darker, curve represents the orders placed to the supplier to fulfil this demand. Normally, the variability of consumer sales is far lower than it is for supplier orders.
This simple analytic tool can be used to show how demand changes along the supply chain in varying time buckets. This information then can be used as the basis for decision making and further analysis to try to redesign the value stream configuration, manage the fluctuations, reduce the fluctuation or to set
up dual-mode solutions where regular demand can be managed in one way and exceptional or promotional demand can be managed in a separate way.
(6) Decision point analysis - Efficient consumer response/logistics
Decision point analysis is of particular use for “T” plants. The decision point is the point in the supply chain where actual demand pull gives way to forecast-driven push. In other words, it is the point at which products stop being made according to actual demand and instead are made against
forecasts alone.
Gaining an understanding of where this point lies is useful for two reasons:
(1) With this knowledge it is possible to assess the processes that operate both downstream and upstream from this point. The purpose of this is to ensure that they are aligned with the relevant pull or push philosophy.
(2) From the long-term perspective, it is possible to design various “what if” scenarios to view the operation of the value stream if the decision point is moved. This may allow for a better design of the value stream.
(7) Physical structure mapping - New tool
Physical structure mapping is a new tool.
The tool is illustrated in Figure and can be seen to be split into two parts,
namely: volume structure and cost structure.
The volume shows the structure of the industry according to the various tiers that exist in
both the supplier area and the distribution area, with the assembler located at the middle point. In an example, there are three supplier tiers as well as three mirrored distribution tiers. In addition, the supplier area is seen to include raw material sources and other support suppliers (such as tooling, capital equipment and consumable firms). These two sets of firms are not given a tier level as they supply to the assembler as well as with the other supplier tiers.
The distribution side includes three tiers as well as a section representing the after-market (in this case for spare parts), as well as various other support organizations providing consumables and service items. This complete industry map therefore captures all the firms involved, with the area of each part of the diagram proportional to the number of firms in each set.
The second diagram maps the industry in a similar way with the same sets of organizations. However, instead of linking the area of the diagram to the number of firms involved, it is directly linked to the value-adding process (or, more strictly to the cost-adding process).
The value analysis or function analysis tools employed by industrial engineers can be focused at the complete industry or supply chain structure. Such an approach may result in a redesign of how the industry functions. An analysis similar to the application of the process activity mapping tool can be made to try to eliminate activities (firms) that are unnecessary, to simplify the activity performed by others, combine yet others and to seek sequence changes that will reduce waste.
What is the objective? The objective is to develop a lean value stream. Let characterize the present value steam as fat value stream.
https://archive.org/stream/industrialorgan00diemgoog/industrialorgan00diemgoog_djvu.txt
INDUSTRIAL ORGANIZATION AND MANAGEMENT
HUGO DlEMER, B.A., M.E.
Professor of Industrial Engineering, Pennsylvania State College;
Consulting Industrial Engineer; Author of Factory Organization and Administration
La Salle Extension University, Chicago
Copyright, 1915
Page 44
Process-mapping
Process-mapping consists of the charting of the general processes involved in the industry. Naturally, analytic manufacturing would present a different type of process-mapping from that of synthetic manufacturing. Similarly, an industry employing consecutive processes would present an entirely different process-mapping from that of an industry in which simultaneous processes are the rule. For instance, a linseed-oil factory is an extractive or analytic industry and would require an entirely different process-map from the one needed by a cement mill, which is a synthetic industry. Again,, a rail mill is a continuous process and requires entirely different process-maps from those of a sewing-machine factory, which typifies simultaneous processes followed by assembling.
Preliminary general process-maps can be made for a given industry by listing first the general operations. If these are all consecutive, we shall have the list in one column, if some are simultaneous, they will be in several columns. Then we can decide definitely, from our knowledge of the processes, which of them require separate buildings and which can be housed together, also which processes must be on the ground floor and which may be on upper floors. For example, it is easy to decide that painting agricultural machinery by the dipping process should be in a separate building from the machine work on the metal parts, and that assembling large boilers must be done on the ground floor.
We can now roughly sketch a phantom-perspective view of a building or group of buildings devoted to processing, for the present omitting power-plant and all service equipment. We may indicate in colored crayons or colored inks the various principal processes and the paths for the flow of materials; supplies, and work in process, as well as by-products and waste, if any. Figures 10, 11, 12, and 13 are simple forms of preliminary process- maps.
Routing of Individual Parts or Classes of Materials
Routing is different from process-mapping in that it traces the path of a single part. For instance, in making a process-map for an automobile factory, we have before us an entirely different task from that required if we route a crank case to be made in that same factory. To route the crank case, we inspect the blue-print and list the separate operations to be done. Process-mapping is a generalized survey of the whole industry. Routing is a detailed investigation which, when thoroughly built up, may materially modify preliminary process-mapping. A well-organized system of routing and a good stock of routing records covering the product form the very best basis for an intelligent process-map. Of course, in starting an entirely new industry the experience and judgment of the men in charge of the productive end of the enterprise form the only basis for process-mapping. Figure 14 is a typical routing card giving the operations to be performed on an individual part.
Process Waste Visualization Charts - Proposal by Narayana Rao
Process waste elimination is an important objective of scientific management and industrial engineering disciplines. Frank Gilbreth proposed process charts to visualize and improve processes.
Taiichi Ohno and Shigeo Shingo combination brought of the 7-Waste Model and created a strong focus on identifying and eliminating waste.
The 7-Waste Model was further extended by others in more wastes. The flow process chart with five symbols can be further developed to identify more wastes and operationalized the extended 7-Waste Model.
The visualization chart can be record the follow events, flows or quantities
Storage
Transport of material
Movement of Operator
Set up of Machine
Uploading material
Batch quantity
Processing or Operation
Unloading material
Inspection
Defects or Rejections
Rework
Temporary delays
Idle time of machine
Idle time of operator
