Lean tools and their applicability to the process industry

The process industry (food & beverage, liquids, sheet goods, solid & fluid packaging operations) differs from the parts manufacturing and assembly industry, where the Lean, 6 Sigma and Theory of Constraints methodologies were developed.

Here we list Lean tools and comment and how they can be applied to the process industry. In some cases they can’t!

We have used many references for this list but the most useful resources were Lean for the Process Industries by Peter King¹, Liquid Lean, Developing Lean Culture in the Process Industries by Raymond Floyd² and Top 25 Lean Tools & Techniques the leanproduction.com website³.

Lean Tool What Is It?³ Applicability To The Process Industry
5S Organize the work area:

  • Sort (eliminate that which is not needed)
  • Set In Order (organize remaining items)
  • Shine (clean and inspect work area)
  • Standardize (write standards for above)
  • Sustain (regularly apply the standards)
5S can be a useful way to gain employee engagement in an improvement effort and as a first step in visual management.

Processing facilities, particularly Food and beverage manufacturing facilities, are by their nature hygienic so there must be a clear value proposition attached to a 5S effort in the process industry.

If there isn’t a clear value proposition then a 5S effort can use up a lot of resources and become an activity akin to polishing the marbles.

Andon Visual feedback system for the plant floor that indicates production status, alerts when assistance is needed, and empowers operators to stop the production process. Most continuous processes cannot be stopped without severe quality, continuity, and even safety consequences.

If Andon systems are used in the process industry at all they must be designed to give immediate feedback but not compromise the product/material.

That said, today’s high tech monitoring equipment can be used to notify operators as soon as a process is running out of specification.

If this is done in a clever way it can serve to create feedback write at the source of a quality problem.

Bottleneck Analysis Identify which part of the manufacturing process limits the overall throughput and improve the performance of that part of the process. In parts manufacturing and assembly, people tend to be the rate limiting factor so managing bottlenecks is often a matter of managing people and leveling tasks. In processing plants, throughput is limited by equipment capability, not by labour.

So in the process industry, managing the bottleneck is a matter of optimising the performance of the bottleneck resource; protecting it from upstream and downstream problems. This can be quite a complex problem requiring significant industrial engineering and ops research understanding.

Capacity Improvement Set targets for the 3 main components of capacity:

  • Takt Time
  • Up Time
  • Scrap
Most of the Lean literature focuses on capacity improvements for paced assembly lines which are more to do with labour productivity.

Asset productivity is far more important to the effectiveness of a process plant.

These measures are still important for the process industry but they need to be adapted to make them relevant and reflect the statistical nature of the operating platform.

Cellular Manufacturing Moving a factory layout from process centre logic to U- or L- shaped arrangements where all necessary processes are contained in one cell. Because of equipment size and inter-connectedness it is often impractical to arrange lines in the process industry into U- or L-shaped arrangements.

Process factories however, can still reap huge benefits by managing flow in a cellular fashion. Creation of virtual cells delivers the following advantages;

  • flow usually becomes faster and much easier to understand, visualise and manage
  • flow tends to be much more continuous with minimum WIP for sequencing and therefore fewer handling losses and costs
  • quality improves because variability is reduced and feedback is more immediate
  • performance improves with operator consistency and more effective root cause analysis- performance data becomes more reliable facilitating better improvement outcomes
Continuous Flow Manufacturing where work-in-process smoothly flows through production with minimal (or no) buffers between steps of the manufacturing process. Processes in the process industry are almost always continuous flow.

Buffers cost a lot of money in the process industry. Therefore, they are usually smaller than they need to be to delivery a high efficiency outcome.

Buffers are a very necessary part of delivering products reliably to customers its just that the art of sizing them properly has been lost as a result of so-called Lean practitioners refusing to recognise (and educate people about) their importance.

Gemba (The Real Place) A philosophy that reminds us to get out of our offices and spend time on the plant floor – the place where real action occurs. This is a very good idea although seems like common sense.
Heijunka (Level Scheduling) A form of production scheduling that purposely manufactures in much smaller batches by sequencing (mixing) product variants within the same process. Heijunka is still possible in the process industry however the complex nature of changeovers (i.e. changing over from one “live” material to another) makes the development of a level schedule more complex.

Dupont™ have developed a Product Wheel methodology for level schedule development which takes into account changeover complexity while minimising run lengths and inventories.

Hoshin Kanri (Policy Deployment) Align the goals of the company (Strategy), with the plans of middle management (Tactics) and the work performed on the plant floor (Action). This is a necessary part of any business. The extent to which a certain approach to policy deployment can be labelled Lean is a bit unclear.
Jidoka (Autonomation) Design equipment to partially automate the manufacturing process (partial automation is typically much less expensive than full automation) and to automatically stop when defects are detected. Jidoka builds in quality at the source by providing equipment with the intelligence to stop automatically or provide clear visual cues when it senses it is producing off-quality material.

Jidoka is as much as state of mind as it is the specific technology embedded in the equipment.

The Jidoka mind set judiciously incorporating Andons, Poke-Yoke is even more important in the asset-driven process industry.

Just-In-Time (JIT) Pull parts through production based on customer demand instead of pushing parts through production based on projected demand.

Relies on many lean tools, such as Continuous Flow, Heijunka, Kanban, Standardized Work and Takt Time.

Achieving Pull in the process industry is very important. It’s just that there is much confusion (and often very heated debate) on what Pull means.

Here is the best definition we have found:

A system that produces to replenish material that has been consumed, or material for which there are firm orders needing to be filled immediately, and in which flow is managed and synchronised by current conditions in the operation.¹

One slightly imperfect but useful test is to ask if current production is scheduled based on forecast; if so it is almost always push. If current production is based on current conditions on the plant floor and within the extended supply chain, it is most likely pull.

Many process plants do not lend themselves to starting and stopping quickly according to pull signals. Consequently run lengths need to be longer to achieve a reasonable trade-off between changeover cost and inventory holding costs.

This challenge can be addressed by taking an extended supply chain view of inventory management and level scheduling.

Kaizen (Continuous Improvement) A strategy where employees work together proactively to achieve regular, incremental improvements in the manufacturing process. Combines the collective talents of a company to create an engine for continual improvement. A structured approach to deploying continuous improvement activities is a hallmark of any improvement system whether that be Lean, 6 Sigma or Theory of Constraints.

In all cases, the key is to have a clear means of prioritisation.

This is particularly important in the processing industry where the proportion of labour available to carry out this work is much lower and where the environment is more complex driven by machine interaction with the product rather than human interaction with the product.

Kanban (Pull System) A method of regulating the flow of goods both within the factory and with outside suppliers and customers. Based on automatic replenishment through signal cards that indicate when more goods are needed. Kanbans are generally unnecessary inside a processing plant because buffers, if they exist, are fully automatic.

Kanbans can be used for the management of raw materials or finished goods. However, if they are used, then it is usually only possible to deploy this methodology to localised and long standing freight, warehousing and material suppliers.

In any case the performance of a Kanban solution is more to do with buffer design and sizing than it is to do with the card system.

KPI (Key Performance Indicator) Metrics designed to track and encourage progress towards critical goals of the organisation. Strongly promoted KPIs can be extremely powerful drivers of behaviour – so it is important to carefully select KPIs that will drive desired behaviour. KPI’s are essential to any business, Lean or otherwise.
Managed Buffers Managed Work In Process (WIP) used to manage operations that contain more than one process.

Each process is decoupled to a level that allows each to operate independently of the others to an acceptable level.

Managed buffers are an important part of the Lean arsenal. Unfortunately, this gets lost in the “all inventory is waste” catch cry.

Managed buffers are an important part of delivering a high-efficiency production platform.

Managed buffers in the process industry are usually fully automated. Therefore, it is so important to size these buffers correctly when the process is being designed and installed.

Sometimes installing additional buffers (tanks, accumulation, conveyors, etc) can be a clever, low-cost means of increasing total plant performance.

Muda (Waste) Anything in the manufacturing process that does not add value from the customer’s perspective. Incorporates the 7 wastes:

  • Waiting
  • Over-production
  • Rejects/Rework
  • Motion
  • Over-processing
  • (Excess) Inventory
  • Transportation
The 7 wastes are one enduring and powerful legacy of the Lean movement.

Waste reduction is relevant in any industry and therefore education about the 7 wastes is helpful almost anywhere.

The trick in the process industry is to prioritise limited resources towards the reduction of waste that will have the biggest impact on total supply chain system performance.

Overall Equipment Effectiveness (OEE) Framework for measuring productivity loss for a given manufacturing process. Three categories of loss are tracked:

  • Availability (e.g. down time)
  • Performance (e.g. slow cycles)
  • Quality (e.g. rejects)
OEE was designed for the parts manufacturing and assembly business. It’s application in these environments, where workstations are fairly defined and contained, can be quite helpful as part of a Total Productive Maintenance initiative.

In the process industry we think that the “Uptime” metric is lesser known but more applicable for interconnected workstations in flow lines.

The final Uptime figure or % is the same as OEE but the categories are different;

  • Crewed Time
  • Usable Time
  • Utilised Time
PDCA (Plan, Do, Check, Act) An iterative methodology for implementing improvements:

  • Plan (establish plan and expected results)
  • Do (implement plan)
  • Check (verify expected results achieved)
  • Act (review and assess; do it again)
This type of structured approach is helpful in any environment. Each improvement system has its own cycle.

6 sigma has the Define Measure Analyse Improve Control (DMAIC) cycle.

The Theory of Constraints has the Process of Ongoing Improvement (POOGI)

Poke-Yoke (Error Proofing) A problem-solving methodology that focuses on resolving the underlying problem instead of applying quick fixes that only treat immediate symptoms of the problem.

A common approach is to ask why five times – each time moving a step closer to discovering the true underlying problem.

The system can be modified once the root cause has been identified such that the re-occurrence of the problem is impossible (e.g. error proofing using jigs)

The automated, technology intensive nature of the process industry can make root cause analysis quite complex, sometimes requiring significant specialist resource.

Once the root cause has been identified however, the automated nature of the process means that error proofing using fail-safe controls is often easy too institute, although sometimes quite costly.

Short Interval Control A factory-floor process that engages team members to review performance data three or four times within their shift to assess where they need to focus their efforts to improve performance. Another great way to get front-line employees engaged.

The process industry has a relatively low labour pool compared to other industries such as the car industry. Also the ability of the front-line worker to make substantial, individual impact on the production system is limited in the process industry because of its complex, asset-driven nature.

Deployment of a Short Interval Control system in a process environment will have short term gains as “low hanging fruit” is picked.

Over the longer term however, more impactful benefits will only accrue if teams are focused towards localised improvements that have been identified has having a big impact on the broader supply chain system.

Single Minute Exchange of Die (SMED) or Quick Changeover (QCO) or Set-up Reduction Reduce setup (changeover) time to less than 10 (single) minutes. Techniques include:

  • Convert setup steps to be external (performed while the process is running)
  • Simplify internal setup (e.g. replace bolts with knobs and levers)
  • Eliminate non-essential operations
  • Create standardized work instructions
This technique is still very powerful in the process industry.

Quick changeover (QCO) is the most useful name.

The Product Wheel (see Heijunka above) should be developed first to identify those changeovers that have the biggest impact on the standard, levelled schedule.

Six Big Losses Six categories of productivity loss that are almost universally experienced in manufacturing:

  • Breakdowns
  • Setup/Adjustments
  • Small Stops
  • Reduced Speed
  • Start-up Rejects
  • Production Rejects
These productivity losses are indeed resident in all manufacturing businesses.

The trouble is that they can be resource pits. No-one ever got the sack for reducing these losses.

The biggest waste of labour $’s occurs when an unprioritised approach is taken to reducing these losses.

We have seen lots of resources expended on reducing losses that are not significant at all in the broader supply chain context. For example;

  • spending labour and maintenance expense reducing a changeover time that could be easily removed by clever schedule leveling.
  • Reducing product-specific breakdowns on a product that is about to be delisted.

In a complex manufacturing environment such as in the process industry, there are plenty of targets. It just that they don’t all have to be shot at.

SMART Goals Goals that are: Specific, Measurable, Attainable, Relevant, and Time-Specific. A well known, common sense, framework.
Standardised Work Documented procedures for manufacturing that capture best practices (including the time to complete each task).

Must be “living” documentation that is easy to change.

The complex nature of most processing environments makes this exceptionally important.

Getting the documentation in place is one thing, getting people to access it and conform to procedures is another thing.

Takt Time The pace of production (e.g. manufacturing one piece every 34 seconds) that aligns production with customer demand. Calculated as Planned Production Time / Customer Demand. Definition of a Takt Time is particularly important on a paced assembly line. Every resource on the line must be paced to meet the Takt Time. Hence in these environments Takt Time is a tangible, line of sight metric.

Takt is a German word meaning rhythm or measure.

In a production context Takt Time means the average time between the start of production of one unit and the start of production of the next unit when these production starts match the rate of customer demand.

Flow lines, not paced production lines, are commonly used in the process industry. In these environments there is usually one machine which sets the pace of a flow line which we call the Drum (in-keeping with the rhythm idea of Takt and also aligning Takt with key concepts in the Theory of Constraints).

In the process industry, Takt time is calculated for each product at the Drum. As with paced assembly lines, the Takt time is calculated from a levelled schedule. Paced assembly lines use a Heijunka box to level the schedule and align it with demand whereas the process industry uses Product Wheels (see Heijunka above).

Total Productive Maintenance (TPM) A holistic approach to maintenance that focuses on proactive and preventative maintenance to maximize the operational time of equipment.

TPM blurs the distinction between maintenance and production by placing a strong emphasis on empowering operators to help maintain their equipment.

Asset productivity is far more important to the effectiveness of a process plant than is labour productivity.

Therefore, the process industries have an even greater need to do everything within reason to improve the reliability and uptime of the equipment and thus a greater need for the benefits that Total Productive Maintenance can bring.¹

TPM plays such an important role in the process industry that some businesses choose to use TPM as the banner under which all Lean improvement work is done.

A TPM implementation in the process industry must be carried out in a very structured way to minimise costs. The four implementation steps must be nurtured in the following way:

  1. Focused Improvement should always be related to the broader supply chain context and incorporate a clear understanding of the statistical nature of the production platform.
  2. Autonomous Maintenance should be scaled gradually to ensure that key personnel are identified and transitioned responsibly with correct support and resources.
  3. Planned Maintenance Programs should be designed and implemented for maximum return on investment.
  4. Operations and Maintenance Skilled training must be carried out with the end in mind. Some people will need to be up-skilled to “virtual engineer” status whereas others will just need to know how to interpret, and act upon, visual cues at their workstation.
Value Stream Mapping (VSM) A tool used to visually map the flow of production. Shows the current and future state of processes in a way that highlights opportunities for improvement. Value Stream Maps are just as important in the process industry as they are in the parts manufacturing and assembly industry (e.g. car manufacturing).

Because the process industry is so capital intensive, entire factories can represent a single workstation or data box on a VSM.

Therefore care must be taken to clearly manage the distinction between a VSM and a process map.

We have designed the Bullant Filters as a means of handling the creation of the types of complicated process maps found in the process industry.

Also VSM’s in the process industry should incorporate unique attributes such as Product Wheels (see Heijunka above).

Visual Factory Visual indicators, displays and controls used throughout manufacturing plants to improve communication of information. People sometimes reject the notion of visual management of plants found in the process industries.

Equipment is often very large, blocking any possibility of line of sight visibility. The materials being processed are frequently contained in tanks, silos, pipes, ovens, or otherwise removed from sight.

These are minor limitations compared to the benefit that can be had by applying the other components of visual management:

  • Workplace cleanliness and organisation brought by 5S
  • Visual scheduling of the operation, at the operation, in real time
  • Electronic Andons to indicate problems and things needing response
  • Visual metrics
  • Communication with management, at the place where work is being done
  • Visual equipment condition indicators.¹

¹ – Lean for the Process Industries, Dealing with Complexity, by Peter L. King, CRC Press, 2009.
² – Liquid Lean, Developing Lean Culture in the Process Industries, by Raymond C. Floyd, CRC Press, 2010.
³ – Top 25 Lean Tools & Techniques from the leanproduction.com website.