How to Impact Human-Machine Interface (HMI)

Effective communication and a good user experience ensure Original Equipment Manufacturing is simple, by design, for vertical form fill seal machines

By Mike Krummey, Electrical Engineering Manager at Matrix

Do you ever wonder why some companies make things more complicated than they need to be?

That’s been a puzzling question for me, especially when it comes to the Human-Machine Interface (HMI) and control system hardware on vertical form fill seal machines (VFFS). Complexity when needed for proper machine performance is unavoidable.  However, when original equipment manufacturing (OEM) limits complexity, it maximizes reliability and minimizes the total cost of machine ownership.

Unfortunately, some machine builders inadvertently create an HMI application that ends up being convoluted and difficult to navigate. This application may seem ‘normal’ to that OEM, but not to the end user.  The end user experience needs to be considered to ensure solutions are intuitive to navigate, and settings are easy to understand.

Simple HMI is vital for efficiency

Simplicity in the HMI running your VFFS machine is vital for efficiency. Employees of different skill levels are going to be responsible for setting up and running the machine. It’s important to make it easier for your operators to be successful in their job operations, and to have a deep understanding of your team’s needs. Whether the operator is new to the industry, or has been around VFFS machines for years, the HMI application needs to be simple and intuitive for anyone to use.

Extending this concept of simplicity further, it’s important to work with your OEM VFFS supplier early in the process by discussing the production goals of your new machine. Whether it’s launching a new project from scratch, or replacing obsolete equipment, discussions including the HMI manual pages should occur. Ask for a machine manual from a similar machine model. Carefully review this documentation and put yourself in the position of being an operator or set-up person attempting to use the machine.

Effective communication starts by asking the right questions

Communication is a key element to successfully select the right VFFS machine for your application. Effectively communicating your current and desired production rates to your supplier is important.  Information that is important to define an application includes:

• What do you want to put in the bag and what is the size for each bag?
• Have you developed a film type or graphic design for the bag?
• How many pounds of product an hour would you like to package?
• Are there special environmental considerations like wash down?
• What is up-line? (e.g., scales, augers, cup fillers)
• Are there down-line automations such as conveyor systems planned?

Having this information readily available before starting any conversation with a potential machine supplier will advance the discussion efficiently. Often at trade shows I will be asked “how fast can your bagger go?”  While this is a valid component of any packaging system discussion, it is not the most effective way to begin conversations with an OEM. An OEM needs to understand the full scope of your project, and that starts with basic engineering:

• What are your requirements?
• Do your packaging lines have space limitations?
• Do you have enough building height for a VFFS machine?
• How many hours in a shift will the machines be running?
• What does your up and down line look like from filling equipment to end of the line equipment?

Standardization delivers better efficiency

For the control system of your new VFFS machine, it may be best to look for machine models that will not require any custom software for your application. Start by looking for standardized features and options in the programmable logic controller (PLI) and HMI. This kind of standardization usually provides superior long-term service support as well as an assurance of proper performance. An OEM with all-inclusive standardization ensures everyone on the sales and support team is familiar with the machines.  A customized machine requires a modified custom control system for the application, and is often more difficult to troubleshoot and service.

In some parts of the packaging market there is a prevailing thought that customization will do a better job because it’s designed just for you. That’s not necessarily true. It is actually important to consider a comprehensive standardized controls package that will handle everything you are going to need the machine to do. This can also reduce costs, delivery time and the overall cost of ownership of the machine. Purchasing a VFFS machine with a powerful standardized control system means you are receiving the best components, but at a reduced cost when compared to custom-built controls.

Standardized machines can have better reliability

Another benefit of going with a standardized VFFS machine is that it is likely to have fewer parts. Custom-built machines are going to have more components and may be more difficult to operate, typically are more expensive, and have longer delivery times. More parts mean more chances of failure when compared to a machine with fewer parts. Thus, your overall cost of ownership goes down with a standardized machine as the reliability goes up.

Finally, if you have a custom-built machine control system, that complexity is going to likely extend to the HMI application as well. You are likely going to find the HMI more challenging to navigate and less intuitive to use. This reality will defeat the operational efficiency of the machine. Control systems that are simple, efficient, and standardized are going to work better for you and your company in the short and long run.

Focus on the human-machine experience, not the hardware

When shopping for new VFFS machines, it is wise to separate the HMI application from the HMI hardware. Regrettably, people often link those two components together when comparing different manufacturers’ VFFS machines. You should really focus in on the functionality of the HMI application, with the hardware running it as a secondary consideration. A good analogy would be you want to watch Monday Night football and it doesn’t really matter what brand of TV it is being viewed on, it’s the content you want. Of course, the reliability of that hardware does play a critical role (nobody wants the TV to quit working).

When focusing on the content of the application running on the HMI, consider these items:

• What do the touchscreens and pages look like in terms of color usage, font size, ease of readability?
• What is the content, how are pages organized, how easy is it to understand settings?
• Are steps provided onscreen to troubleshoot problems? Are alarms clear and status indicators simple to understand?
• How are security levels handled? Are passwords editable?

Always remember, the HMI application impacts the user interface between OEM’s of VFFS machines.  The HMI application can matter more than the HMI application for the end user. The HMI hardware used by any reputable OEM will be name brand and backed by a minimum one-year warranty.

Seek suppliers with expertise in your market

Successful installation of a VFFS machine begins with clear communication about your application. When working with different suppliers of these machines, look for options with experience and expertise in your market. Once you have narrowed the list of potential suppliers, look for simplicity in the control system and HMI application. A well-built VFFS machine is going to be rooted in simplicity and a built-in standardized controls package including everything you need to successfully bag your product. While the technology in VFFS machines is more advanced than ever before, it really doesn’t need to be complicated to operate. Seeking out an OEM that strives to keep things simple is a great start to your long-term packaging success.

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