Reducing Transportation Waste With A Real-Time Asset Location System

According to Lean Manufacturing methodology, there are seven major wastes that prevent a company from reaching the maximum effectiveness and efficiency in production. Bryan McWhorter, a Lean expert and an author of the Introduction to Lean Manufacturing, proposes using TIMWOOD as an acronym to memorize them. Each of the letters means a certain waste in manufacturing processes:

1. T — Transportation
2. I — Inventory
3. M — Motion
4. W — Waiting
5. O — Overproduction
6. O — Overprocessing
7. D — Defects.

Among them, transportation waste is one of the most common problems facing any manufacturing process.

Simply explained, transportation waste is an unnecessary movement of people and equipment used in manufacturing processes as well as double handling of materials. For example, a forklift may take further paths than necessary, thus increasing process times and the risk of unnecessary work and equipment wear.

Transportation waste. Image Credit: The Lean Way

To avoid this type of waste, managers of industrial fleets need to optimize their routes to maximize the effectiveness of intralogistics and material flow e.g. by reducing the number of empty trips, or unnecessary detours from A to B. This can lead to significant savings (e.g. on Capex as fewer assets are needed for the same job) or increased productivity as more can be done with the same assets.

A preferred lean manufacturing tool used as a first step to achieve these goals is called a spaghetti diagram, which is a visual representation of a movement of an asset (usually a forklift), or an employee during a certain process (such as milk run) on the factory floor. A Lean Manufacturing practitioner typically draws a spaghetti diagram based on their own observations and by hand in order to:

• Understand the actual movement of people, assets, or materials during a certain process
• Identify redundant and wasteful movements (transportation waste) that should be eliminated to speed up manufacturing, intralogistics, and other processes
• Determine a standard process time along with necessary buffers in order to improve production planning.

Drawing of spaghetti diagrams and analyzing the movement is a challenging and time-consuming task because it requires manual input. It often means walking behind or being driven around by a milkman in the tugger train with a stopwatch and a piece of paper. As a result, the manual drawings are not easy to interpret, because they tend to get cluttered and difficult to follow.

Figure 1. A manually drawn spaghetti diagram. Image Credit: Cadet

There have been numerous attempts to improve this process with Excel tables and other tools, but with the emergence of Industry 4.0 technology, namely real-time location systems (RTLS), this task actually becomes efficient and functional.

In the next section, we’re going to explore how a RTLS can help manufacturing managers and Lean manufacturing practitioners to reduce transportation waste thanks to a digital spaghetti diagram such as the one we provide to our clients at Indoorway.

How to Reduce Transportation Waste with Indoorway RTLS

Indoorway RTLS proposes a new way of creating spaghetti diagrams: real-time tracking of assets and employees involved in processes such as manufacturing and intralogistics by mapping their movement on digital floor plans.

Step 1. Map Asset Movement

To demonstrate how a logistics manager can reduce transportation waste in processes, we’re going to use a forklift tracking case study we’ve completed recently.

Tracked asset: forklift

Site: Production facility (automotive)

Process: Intralogistics; Material flow

Small Indoorway tags were attached to the forklift so its location could be tracked via the Visual Dashboard in real time by the intralogistics management team. The forklift was monitored for four weeks, with all data about movement during shifts saved and available for further analysis.

The digital spaghetti diagram (see Figure 2) was then generated by Indoorway on the digital plan of the building to visualize the movement of the selected asset. Such diagrams can be generated automatically based on client criteria e.g. by forklift, by operator, by speed, compared between shifts, etc.

Figure 2. Spaghetti diagram for the tracked forklift representing its movement during the four weeks of monitoring. Areas: U — unloading, H — highway, B/P — parking, W — warehouse, and P — production.

Figure 2 shows that the forklift traveled throughout the entire facility even though it was assigned to stay within standard routes between the Unloading area and Warehouse areas. At this point, it’s time for the logistics manager to assess the diagram and develop solutions for maximizing the productivity of the asset.

Step 2. Analyze the Results

The analysis of the spaghetti diagram by the intralogistics manager revealed two factors that contributed to transportation waste:

• Routing deviations (marked by RD in Figure 2)
• Routing losses (RL in Figure 2).

First, routing deviations are defined as non-standard routes that forklift driver decided to take instead of the ones assigned by the management for the fastest performance. For example, by choosing to go through the warehouse (marked by W), the operator created avoidable risks of collisions and injuries because that area had active personnel and equipment.

Second, routing losses shown in Figure 3 showed that the forklift also traveled to Production areas (P), which was outside its standard routes.

Figure 3. Transportation waste — routing losses and routing deviations — that undermine the effectiveness of internal logistics.

Together, routing deviations and losses are a transportation waste. It means they:

• Can be minimized
• Don’t add value
• Increase risks (such as health & safety risks in this example)
• Indicate a possible non-compliance with standards
• Prolong process times.

Thanks to the spaghetti diagram analysis, tracking a moving asset helped identify two serious problems that undermined the effectiveness of the internal logistics at the site.

Step 3. Make Evidence-Based Changes

Whereas in some cases there may be valid reasons for detours and inefficient routes and no need to worry, often such simple information can lead to discovery of potential problems or risks.

You can only improve what you measure, which means that only having actual and consistent data about how different assets move around, it is possible for logistics managers to work on solutions that will minimize wasted movement without causing collateral damage due to unintended consequences of change.

Minimizing transportation waste becomes a lot easier if you can track the moving asset all the time and define how much time it should spend in certain areas.

An RTLS is an excellent solution for this task because it provides both real-time and historical movement measurement and eliminates the need for observations and manual drawing of spaghetti diagrams. It can also send automated alerts and notifications about variations to the standards based on selected criteria.

If you would like to know how to reduce transportation waste in your manufacturing facility with an RTLS, visit our site indoorway.com or email us directly.