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Chapter 3: Value Stream Mapping

CHAPTER CONTENTS

 

Introduction to Value Stream Mapping

While the last chapter discussed how to raise awareness about environmental wastes across your organization, this chapter will show you how to target Lean improvement efforts within a product’s value stream. The chapter describes ways to enhance value stream mapping to uncover hidden sources of material wastes, identify process improvement ideas, and anticipate regulatory compliance needs.

Key TermDefinition of Value Stream Mapping

Value stream mapping is a Lean process-mapping method for understanding the sequence of activities and information flows used to produce a product or deliver a service. Lean practitioners use value stream mapping to:

  • Identify major sources of non-value added time in a value stream;
  • Envision a less wasteful future state; and
  • Develop an implementation plan for future Lean activities.

Key PointThe power of value stream mapping lies in walking the plant floor, talking to workers, and closely observing how a product is actually made from start to finish. See Appendix A for more information on value stream mapping

 

CASE STUDY: GENERAL MOTORS

General Motors has been integrating Lean manufacturing and environmental initiatives since the 1990s, including kanban, kaizen events, and value stream mapping (VSM). In a more recent effort, the company conducted a kaizen event with a key supplier to enhance the cost competitiveness and on-time delivery of steering column components. GM used VSM and Toyota’s “five whys” technique and observed delays when steering column shrouds were shipped to an outside vendor for painting. Because the shrouds were only painted to cover flaws caused by the die, GM suggested improving the quality of the die and molding the part using a resin of the desired color. The supplier began using a new molding process that removed the need for the painting step. This project saved the supplier $700,000 per year, shortened lead times, and improved on-time delivery to GM.

What This Chapter Will Help You Do

This chapter will help you identify and address the following wastes that can be overlooked in value stream mapping:

  • Raw materials used by processes versus materials needed for the product;
  • Pollution and other environmental wastes generated in the value stream; and
  • Flows of information to regulatory agencies about environmental compliance management activities.

Analyzing these flows in value streams at your company could reveal substantial opportunities to reduce costs, improve production flow, and save time, as well as improve environmental performance and the health and safety of the workplace. Early attention to environmental considerations and involvement of EHS staff when planning for future Lean improvement efforts in a value stream can also help your company address potential regulatory compliance issues, minimize delays, and avoid the need for costly rework.

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How to Incorporate Environmental Considerations into Value Stream Mapping

Overview of Value Stream Mapping Opportunities

There are at least five ways to explicitly address pollution and natural resource wastes using value stream mapping.

How-to Steps
  • Use icons to identify processes with EHS opportunities.
  • Record environmental data for processes in value stream maps.
  • Analyze materials use versus need in a “materials line” for value stream maps.
  • Expand the application of value stream mapping to natural resource flows.
  • Find Lean and environment opportunities in future state value stream maps.

1. Use Icons to Identify Processes with EHS Opportunities

New ToolSome processes warrant a special focus on EHS issues because they can pose hazards to workers, have permits and other regulatory requirements, and/or represent good opportunities to reduce pollution and material costs. To raise awareness about these risks and opportunities, use a red dot or an EHS icon (see example below) to identify these processes on value stream maps.

Figure 2: Example Process Box with EHS Icon

Figure 2:  Example Process Box with EHS Icon

New ToolStaff with EHS expertise can help your value stream mapping team determine where to place EHS icons on value stream maps. The textbox below also lists 10 Common Manufacturing Processes with Environmental Opportunities.

10 Common Manufacturing Processes with Environmental Opportunities
  1. Metal casting
  2. Materials treatment
  3. Metal fabrication and machining
  4. Cleaning and surface preparation
  5. Bonding and sealing
  6. Welding
  7. Metal finishing and plating
  8. Painting and coating
  9. Chemical and hazardous materials management
  10. Waste management

It is essential for EHS staff to participate in planning for and conducting Lean events on these processes because of the potential risks of non-compliance and the potential hazards to workers. EHS Key Pointstaff can also bring fresh ideas and new tools to add to the solution set. Chapter 4 provides more information about how to identify and address EHS issues during kaizen events.

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2. Record Environmental Data for Processes in Value Stream Maps

A second way to uncover environmental wastes in value stream mapping is to select one or two environmental performance metrics to measure for each process in the value stream. A list of types of environmental metrics you could use can be found on page 15; Appendix B provides more detailed information about metrics.

Key PointIf your company does not already have these data available at the process level, you may need to invest additional time and/or resources to collect environmental data about the current state. For example, you could weigh the amounts of scrap and solid wastes generated by each process during a shift, or use energy meters to estimate typical energy use. This extra investment in data collection, will allow you to appropriately target Lean improvement efforts on the highest priority problems, and thereby achieve the greatest benefits.

Figure 3 shows a current state value stream map that includes both EHS icons and environmental data for each process. In this case, each process box lists the amount of hazardous waste generated by that process per shift in addition to commonly collected data on cycle time (C/T), changeover time (C/O), and machine uptime.

Figure 3: Current State Value Stream Map with Environmental Data
(click here for a larger version)

Figure 3:  Current State Value Stream Map with Environmental Data

To Consider
  • Which environmental metric(s) would you choose to include in value stream maps at your company?
  • Does your company or facility have environmental goals and targets that could be identified on value stream maps?
  • What processes at your company do you think might have the greatest opportunities for environmental improvement?

3. Analyze Materials Use Versus Need in a “Materials Line” for Value Stream Maps

Key PointValue stream maps typically examine the time it takes to produce a product and the proportion of that time that is value added, but they do not focus on the resources consumed and wasted in the development of that product. Raw materials are often a large source of a product’s costs, so looking explicitly at the material flows in a value stream is another way to leverage greater gains.

One way to do this is to draw a “materials line” on the bottom of a value stream map that shows two types of data:

  • Amount of raw materials used by each process in the value stream; and
  • Amount of materials that end up in the product and add value from a customer’s perspective.

New ToolThe materials line is analogous to the “timeline” on value stream maps, and can be developed for any type of resource (e.g., water, energy, total materials, and/or a critical substance used in the product). Figure 4 shows an example of a materials line. In this example, the milling and welding processes consumed 135 pounds of materials, but only 85 pounds were actually needed and added to the product. Fifty pounds of materials were wasted.

Figure 4: Example “Materials Line” Showing Materials Use Versus Need

Figure 4: Example “Materials Line” Showing Materials Use Versus Need

Once you collect data for the materials line, you may notice large differences between the amount of material used and the amount needed for the product. This can help you target Lean improvement efforts on the largest sources of waste. Figure 5 shows a complete example of a value stream map with a materials line.

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4. Expand the Application of Value Stream Mapping to Natural Resource Flows

In contrast to adding a materials line to a conventional value stream map (as discussed above), you can also use value stream maps to look in more detail at the inputs, outputs, and information flows associated with the use of energy, water, and/or materials. Along with comparing materials use versus need for each process in the value stream, you can examine environmental waste streams (i.e., non-product outputs such as air emissions, wastewater, hazardous wastes, and trash) and the flows of information to environmental regulatory agencies.

Figure 6 displays a water-use value stream map for a product that contains water (e.g., a medical IV bag). This value stream map includes a materials line summarizing the amount of water that is used and needed by each process in the value stream. There are arrows showing the flow of wastewater from each process to the sewer and another arrow depicting the flow of information about wastewater discharges to regulatory agencies.

This type of detailed examination of material flows can help you find hidden sources of waste in the value stream. All three elements of a materials-flow value stream map—the materials line, environmental waste flows, and regulatory information flows—can also be targets for future Lean efforts.

Figure 5: Current State Value Stream Map with Materials Line
(click here for a larger version)

Figure 5: Current State Value Stream Map with Materials Line
 

Figure 6: Water Use Value Stream Map (Current State)
(click here for a larger version)

Figure 6: Water Use Value Stream Map (Current State)

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5. Find Lean and Environment Opportunities in Future State Value Stream Maps

New ToolAll the tools and techniques described thus far in this chapter—EHS icons, environmental metrics, addition of a materials line, and materials-flow tracking—can help you to see environmental wastes in the current state of the value stream as well as identify targets for future Lean implementation activities.

Consider the following Questions about the Future State of a Value Stream when developing the future state value stream map. These questions, along with input from any EHS staff participating in your team, can help to:

  • Envision ways to eliminate environmental wastes in the value stream; and
  • Recognize when Lean improvement events could raise EHS compliance issues and, therefore, require involvement of staff with EHS expertise.
Questions About the Future State of a Value Stream
  • Where are kaizen events (discussed in Chapter 4) needed to address the biggest areas of environmental wastes? These might include:
    • Processes with high energy, water, and/or materials use; and
    • Processes that generate large amounts of solid waste, hazardous waste, and/or pollution.
  • Will any changes be made to the layout of processes marked with an EHS icon or to the chemicals used by those processes? (These changes could have potential implications for regulatory compliance practices.)
  • Can one process use the “waste” material from another process instead of using virgin materials?
  • What would an ideal state for the value stream look like with zero wastes, where products and processes posed no risks to health or the environment, and where there was no need for permits?
  • What steps can be taken now to get to that ideal state?

Figure 7 depicts a future state value stream map that includes kaizen starbursts for environmental improvement opportunities as well as changes to establish a “pull” system to control inventory levels and improve production flow.

Figure 7: Future State Value Stream Map with EHS Icons and a Materials Line
(click here for a larger version)

Figure 7: Future State Value Stream Map with EHS Icons and a Materials Line

Key PointWhen developing the kaizen implementation plan associated with the future state value stream map, remember that Lean events on certain processes (including processes with environmental regulatory requirements and others labeled with EHS icons) may require special attention to EHS issues.

CASE STUDY: BAXTER HEALTHCARE CORPORATION

Baxter Healthcare Corp., a worldwide leader in manufacturing global medical products, adopted a number of Lean techniques to reduce its environmental footprint. Baxter integrated environmental metrics with traditional Lean manufacturing tools, helping the company double in size and revenue while keeping total waste generation close to 1996 levels. Several company plants completed a value stream map (VSM) to find ways to reduce water and energy consumption. One plant developed a VSM and implementation plans by walking through the production process and highlighting water usage and major processing steps. In the VSM, 96 opportunities were prioritized with many graphically represented by starbursts; these opportunities were also included in three future state VSMs. Through the VSM event, Baxter developed an action plan that should save $17,000 over three months and 170,000 gallons of water per day.

 

It is critical to involve staff with EHS expertise early in planning for Lean events on processes with EHS opportunities. EHS staff can:

  • Anticipate changes needed to environmental compliance practices from Lean activities and help implement those changes as quickly as possible;
  • Bring a different perspective to Lean activities and additional ideas for waste-reduction opportunities; and
  • Ensure that Lean activities improve or cause no harm to worker health, safety, or the environment.

In the next chapter you will learn more about how to integrate environmental considerations into the implementation of kaizen events at your company.

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Conclusion

Summary

Value stream mapping is a Lean process-mapping method for understanding the sequence of activities and information flows used to produce a product or deliver a service. Conventional value stream mapping can overlook three types of environmental considerations:

  • Raw materials used in products and processes;
  • Pollution and other environmental wastes in the value stream; and
  • Flows of information to environmental regulatory agencies.

There are at least five ways to explicitly address pollution and natural resource wastes using value stream mapping.

  1. Use icons to identify processes with EHS opportunities in value stream maps, and involve EHS staff in planning Lean events on those processes.
  2. Record environmental performance data for processes in value stream maps, and consider these data in developing a vision for the future state.
  3. Analyze materials used by each process versus materials actually needed for the product, and summarize this information in a “materials line” below the timeline on value stream maps.
  4. Expand the application of value stream mapping to natural resource flows such as energy and water use, by including additional information on materials use, waste streams, and regulatory information flows in the maps.
  5. Consider Lean and environment questions, as well as environmental data included in the current state map, when developing the future state map.

Environmental, health, and safety professionals can help to:

  • Collect environmental performance data for processes in the value stream;
  • Identify processes with environmental opportunities in value stream maps; and
  • Make sure that changes to those processes are managed safely and effectively through Lean implementation.
Your Thoughts

Now that you’ve finished this chapter, reflect on what you read by answering these questions:

  • What did you learn in this chapter that was particularly useful?
  • Do you need any more information to fully understand how to integrate environmental, health, and safety considerations into value stream mapping? Would any other tools be helpful?
  • What other ideas do you have to improve the environmental performance of your company with value stream mapping?

 
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