TRIZ Improves Mars Candy Pouch
Editor | On 05, Jan 2009
By Frederic Mathis
In 2003, Mars (previously called Master-foods) launched new packaging for its bite-size products, including M&M’s, Maltesers, Minstrels, Revels and Mars Planets. The packaging changed from a standard pillow bag (Figure 1) to a standing pouch (Figure 2).
There were several goals associated with the new packaging − all of them designed to increase Mars sales. The goals included:
- Moving the packages from a horizontal pack to a vertical pack for better shelf visibility,
- Enhancing the sharing experience by allowing the pouch to stand open so a consumer could easily reach into the bag or pass it to friends,
- Offering a straight and easy opening that could be re-closed with a sticker attached to the back of the package and
- Making the tear strip at the upper part of the pouch easily removable so it did not block a hand reaching into the pouch and did not alter the aesthetics of the pouch once opened.
A multi-disciplinary team identified the best packaging machine and packaging material to deliver the concept. A micro-perforated line on both sides of the pouch near the easy opening line printed on the design would result in a straight opening. After launching the new packaging, sales increased and the packaging was a market success.
The new packaging changed the way people viewed the bite-size segment and many competitors designed their own version of the pouch or copied the Mars product by buying the same packaging machine. The entire market was affected creating a shift from the standard pillow bags or poor quality standing bags to more premium packs.
Although the new packaging was on the market, it was still in its infancy stage and needed improvements. The S-curve in Figure3 provides a visual of the stages of product development.
The new packaging failed to meet a key consumer attribute â€“ it still did not open in a straight line, affecting the aesthetics. When the consumer tore the pouch open the tear did not follow the perforations, as shown in Figures 4 and 5. The tear lines were erratic and the front and back tears did not connect at the edge of the pouch. As a result, removing the tear strip was difficult and the opened pouch looked awful. The development team needed to fix this before the product could reach the maturity stage on the S-curve.
The back tear followed the perforation line, but the front tear traveled toward the lower side of the pouch making it difficult to remove the tear strip where it remained attached by at least a two centimeter seal. This problem was enhanced when the pouch had a Euroslot, as shown in Figure 6. (A Euroslot is a hole on the package allowing the product to be hung on a display rack.)
The development team tested the performance of the packages and the results were unsatisfactory:
- Only 5 percent of the packages without a Euroslot opened straight and none of the packages with the slot opened straight.
- The torn strip was not easily removed on any of the packages.
- The average distance between the front and back tear lines was 15 millimeters for the regular pouch and 30 millimeters for the Euroslot bags.
The team attempted using a standard trial-and-error method to solve the problem − try one thing, if it does not work, try something else. Although this method may be a result of the natural evolution of the human mind, it is not perfect and can require significant time before attaining the right solution. As Genrich Altshuller, the father of TRIZ (Theory of Inventive Principles), wrote in his book The Innovation Algorithm: “During the process of evolution, our brain learns to find approximate solutions to simple problems. However, it does not develop mechanisms of slow and precise solutions to complex problems.”
The problem was that the inadequate opening impacted a key consumer attribute; the problem needed to be quickly solved.
The development team joined the suppliers in the process during the trial-and-error phase, but soon realized that little could be done to change the material itself. While there were many different film structures and combinations of films with the proper tear properties available on the market, the team faced two problems when it attempted to change the materials: 1)the line efficiency was affected because of the friction generated during the tear or 2) the packaging lost the necessary heat-sealing properties.It became evident that changing the film was not the right solution. Changing the film perforation was not helping either, because the tear did not follow the perforations.
The development team conducted brainstorming sessions in an attempt to find the solution. But again, as Altshuller wrote in his book, “Brainstorming does not eliminate chaotic searching. In reality it makes searching even more chaotic. The absurdity of brainstorming as a searching process is compensated for by its quantitative factor â€“ problems are attacked by a large team. Any gain here is achieved only through the reduction of inefficient attempts along the direction of the Inertia Vector.”
The team was not finding a real step change and needed a new direction. To be quick, efficient and successful, they needed something different, powerful and able to direct their problem solving in a more heuristic way â€“ they needed TRIZ.
Solving the Problem with TRIZ
TRIZ was not new to Mars in 2004. Some (including the author) were trained in TRIZ and the company had previously used TRIZ tools to solve a problem in the coffee machine segment. But, the company had stopped using it and lost its competency. People worked in an emergency mode using trial-and-error and brainstorming methods. Some problem solvers thought using a specific problem solving method was too difficult and/or time consuming.
The development team, however, recognized the potential of TRIZ as a problem solving methodology. The project manager, a TRIZ convert and a TRIZ addict, worked to establish a TRIZ culture and thinking process within Mars.
Finding Concepts with TRIZ
The first step was to define the problem and establish an ideal final result (IFR or ideal outcome). The development team wanted the:
- Material to tear horizontally instead of toward the top or bottom of the pouch.
- Material to tear horizontally and not stop when it reached the Euroslot.
- Tear to follow the shape of the Euroslot but not stop on it.
- Tear to follow the sealing line but not stop on the Euroslot.
- Both walls to be under tension instead of only the side being torn.
- Tear on the front and back of the pouch to meet on the other side of the pouch. When the two tears meet the consumer can easily remove the tear strip. The greater the distance between the tears, the more difficult it is to remove the tear strip.
- If the two walls are near each other at the top of the pouch the tear is straight. Farther down on filled pouch the product moves the walls apart and the tear is no longer straight.
When the pouch had a Euroslot, the tear line was lower on the pouch, and the distance between the walls was greater resulting in a worse tear.
The development team summarized the ideal outcome as a product that allowed a consumer to:
- Easily remove the tear strip, which would occur if tears at the front and back of the pouch met at the same position.
- Tear the pouch open in a straight line, which meant the walls of the pouch needed to be as near as possible to each other, because the distance between the walls impacts the tear.
After finalizing the ideal outcome the team mapped their manufacturing process/system using a TRIZ time-scale matrix that provided them a clear overview of their system, super-system, sub-system and their inter-relationships.
The development team used the TRIZ 76 standards to determine what could be done within the different parts of the system to straighten the tear. The first standard the team used was: Stop a harmful action being harmful: change the object so it is non-sensitive to the harmful action. To change the object so it becomes non-sensitive to the harm, the team needed to hang the pouch from two separate walls into only one. When the walls are connected the tear is straight. The team had several ideas for how to do this at the various system levels:
- Put cold-seal on each side of the wall − when they touch each other they become one
- Seal the area where the tear should occur (heat seal or ultrasonic seal)
- Extract the air so the walls are near each other
- Use a zipper
- Use a multi-layer laminate (Triplex)
- Use static electricity
- Apply Velcro
- Void inside the pouch to attract the walls to each other
- Use a non-deformable material
- Use a more rigid material
- Change the material orientation (at the molecular level)
The second of the 76 standards was: Add another action to intensify/ supplement the effect/ action or add a new (second) field which is more easily controlled. The intent is to improve the efficiency of the perforation, because it is currently insufficient − the tear does not follow it.
Super-system level (supplier process):
- Fancy cut system (increase the number of perforation lines)
- Laser cut (new field)
- Change the shape of the cuts (seesaw type similar to those used on boxes)
- Completely cut one part of the laminate instead of just perforating it
- Make half cuts like on cardboard
- Change the position of the tearing notch
The team used a third standard: Stop a harmful action being harmful: counteract the harmful action with an opposing field:
Super-system level (the pouch making machine):
- Create a thickness in the side walls to stop the tear from traveling downward
- Weaken the material at the side seal so the consumer can remove the tear strip even if the tears on each wall do not join on the opposite side
- Add material or glue during the pouch forming process
- Add something on the side walls to guide the opening
- Use the re-close sticker to guide the opening
- Remove the glue on partial areas to block the tear line
- Use two different glues
- Use stress cracking: high or low temperature effect, with or without pressure
- Change the shape of the Euroslot
During this case study the team used three of the 76 standards and some of the 40 principles of the contradiction matrix − segmentation, in particular. After their analysis of the standards and principles the team met with the suppliers to develop a plan to industrialize the solutions.
Industrialization of the Concepts
When the development team met with the suppliers, they explored the different concepts one-by-one to see which would solve the problem.
I.1) Orientation (no bubble effect): The idea was to see if they could block the “bubble effect” generated by the blown extrusion process that occurred during the fabrication of one of the structural materials. The team thought this might be causing the tear to travel down the pouch as it was bubble shaped.
- Thicker film
- More rigid film
- More layers
II) Get the two pouch walls closer together (glue the walls after the pouch is made):
- Using cold-seal points
III) Guide the opening better:
III.1) Improve the micro-perforation:
- Cut a different layer
- Cut different sides in an alternate way
- Cut all sides at the same place (total perforation after lamination)
- Make several parallel lines
- Use different knife widths
- Use different knife shapes (easy opening system on boxes)
- Segmentation of holes: multiplication of holes (like fancy cuts − coming back to multi-lines)
- Vertical lines: multiplicity of vertical line to create tension differential
Figure 10: Verticle Lines
- Vertical lines at the edge of the pouch to improve the tearing of the top part of the pouch
III.2) Material stress to get an opening orientation:
- Use the cutting reel on the line at the supplier to locally crush the film in the easy opening area
- Heat the cutting reel (material stress)
IV) Create a thicker area to guide the opening:
- Thicker lamination for glue areas
- Increase the glue weight to check the impact on rigidity
- Change glue type
- No glue in the opening area
- Hardening varnish
- Combination of glue and varnish
Figure 14: Combine Glue and Varnish
The Winning Idea and the Validation
Testing and validating these ideas was a lot of work. The most original, clever and easy-to-implement idea eliminated the glue from the laminate in the tear area allowing the tear to stay within the opening area. The development team implemented this idea. The most difficult step in the development process was convincing the suppliers to test it. Initially they rejected the idea (likely due to psychological inertia), but after several trials the solution was validated.
In the final product three lines were added to each side wall to allow for variation in the forming of the pouches. The tear traveled through the middle of the area. If the tear moved away from a straight line, it fell inside the glue-free area and was guided back to the intended tear line. Figure 16 shows that the glue-free lines allowed the tear to travel horizontally across the pouch.
Patenting the Idea
The development team patented the unique idea.
The new packaging system is now on the market as the M&M’s Peanut Pouch.
As for all systems, invention and creativity are journeys along the S-curve and the adventure never finishes. When the development team wanted to transfer the system to other designs with dark colored backgrounds (M&M’s Crispy, with a blue background, and M&M’s Plain, with a brown background) they were faced with another aesthetic problem − the glue-free lines were visible and impacted the look of the pouch. This was not acceptable for marketing, so the team developed yet another solution that is now on the market and has enhanced the aesthetics of the pouch and also improved its opening efficiency.
This study serves as another example of TRIZ as a powerful and innovative problem solving method. The author uses it as a basic development, problem solving and innovation tool, and has used TRIZ to solve other packaging problems, develop new packaging concepts and lead innovation in a new direction. This example only illustrated a few aspects of TRIZ methodology. Applying other TRIZ tools â€“ trend analysis, ideality of a system, functional mapping, etc. − is now bringing creativity to a new level.