Human Machine Interface (HMI)

The User Interface (also known as Human Machine Interface) is generally means of the human (people or users) interact with a particular system such as machine, computer software, device, instrument or complex tool. In other words, it represents a layer that separates a human from a particular system.

The main function of the interface is to allow user manipulate a system as well as allow the system itself produce the effect that the system’s user manipulation. In other words, it makes the function of a system self-evident. Much like a well-designed wizard in a computer’s application software to guide through a process to the user.

As such, the design of the user interface will strongly reflect to the Effectiveness and Efficiency of a system as well as Satisfaction, Learnability and Productivity to the end users. These are to be measured as Usability (also known as Quality Of Use).

The system’s effectiveness and efficiency is crucial to production. Also, well User Interface design may Ensure Operational Safety, Reduce Operation Error (Japanese used the word POKA-MISS) and Improve Productivity. Also, a well design interface helps the user learn the interface with minimum effort and minimum stress when operating the system.

These components (Effectiveness, Efficiency and Satisfaction) are not intrinsic quantities of a goods or product. The designer cannot measure the quantities of the components in a User Interface. Effectiveness is depends on how well the system meet it goals or tasks. Efficiency is depends on how well users understand the system. Satisfaction can only be analyzed from the user feedback and expression when operating the system.

In order to increase a usability of a system, a design process known as Usability Engineering should be applied. The Usability Engineering is a technique that keeps the user in the system design process. It is important in order to maintain the Ease Of Use on a system. A research shows that more than 50 percent of the coding in a software application was devoted to the User Interface. As a summarization, Usability Engineering is as the following.

• Understanding user needs and knowledge by some analysis through questionnaire.


• Understanding user experience.


• Field Observation


• Design Review

ISO 9241 – Ergonomic Requirement For Work With Visual Display Terminal has being produced that covers many areas for a system design.

Well…, how a well designed User Interface ensures operational safety, reduce operational error and improve productivity?

Take a look at the Operation Panel on the figure above, which I have taken from our production floor. It looks pretty much simple. However, each key or switches is labeled by using a term (also known as technical words). As a new operator to this machine, the trainer as well as for the operator will surely need sometimes to learn and familiar with the operation of the machine. It might leads to some operation error if the operator is not well trained. As a result, the safety of the operator and the machine could not be ensured. In addition, the panel is said to be not informative since there is no any display to alert to the user.

Let takes another example on the Computer's Operating System. The old Microsoft DOS operating system has been replaced by the Windows operating system which is rich in Graphical User Interface (GUI). The computer's hard drive is easier to be explored with a click of the Mouse rather than key in the 'DIR' command at the command prompt in the old DOS system. In fact, it might leads to an operation error - Bad Command, which in return, lost in time and cause low productivity. In addition, the GUI mekes the operating system easier to use and learn.

As you may notice, a lot of effort has been goes to the interface design. How well a system is fit to it tasks in order to produce output is how well we design the interface. A well user interface design surely ensure the operational safety, reduce operation error and hence improve productivity.

Due to the Efficiency and Effectiveness of a system as well as the usability of a system. Most of my recent development are in PC based Automation and Technologies. Just because PC is providing such marvelloususer interface in Windows system, huge data storage as well as the flexibility in networking. An automation system can be carefully integrated to improve productivity, reduce human error, ensure operational safety, time to market as well as development cost reduction since more flexible and larger system can be easily integrated through networking.

Drop me an eMail in order to know more about my recent system develoment. By the way, I will discuss about the 'Safety In Automation System' in my up coming article.

Have a nice reading... :)

What Is An ‘Automation’?

I would prefer to descript the word as a combination of hardware (including Mechanical as well as electrical) and software in order to provide a system Self-Dictated so that a routine or a process or task is performed automatically with minimum supervisory.

The hardware, mechanical system, provides a mechanism for the physical requirement of work. Whereas, the electrical system, provides energy to the mechanism resulting a driving event occur such as an indicating light lit up, a door opened or an alarm turned ON. The hardware however is to be monitor and control by the use of a control system such as a Microcontroller (also known as embedded system), PLC (Programmable Logic Controller) or a Computers.

In the early stage of automation, most system is controlled by microcontroller technologies. The code running at microcontroller are normally written using Assembler language or ANSI C programming language. Due to the development cost increase rapidly in more complicated system and time to market concern, engineer start integrate the system with PLC. All the PLC procedure are represented by symbolic structure (also known as Ladder Diagram), which is believe to be more easy to use, easy to learn with minimum effort as well as easy to maintain.

Often, a Human Machine Interface (HMI), formerly known as Man Machine Interface (MMI) are usually implemented in order to let human interact or communicate with machine such as entering operation data into a particular system. As such, the design of the User Interface will strongly reflect to the Effectiveness and Efficiency of a system as well as Satisfaction, Learnability to the user and Productivity to the production floor.

A well design User Interfaces may appear to Ensure Operational Safety, Reduce Operation Error and Improve Productivity. As a result, A GUI PC Based system is being widely used in recent development. In fact, due to its flexibility in networking, a scalable system can be carefully integrated in order to support Quality issues and flexibility in manufacturing process, productivity as well as cost reduction.

One of the most popular Integrated Development Environment (IDE) to me is the Microsoft Visual Basic (one of the products family of Microsoft Visual Studio), which provides all of the computing power necessity, stable and can be easily master the language without hire any guru. Others such as MatLab and LabView are widely introduced at local universities. Others such as C++ and Delphi is also widely used.

The advance of the technologies has seriously replacing human operators in almost any industrial process due to its accuracy, speed, and precision, which would significantly lead to severe unemployment. However, the overall effect of this is remained unclear. This is because skillful workforce is still required to design and maintain such system. Today, innovation has rapidly changed the advance of technology, more and more complicated system was created and needed in the industry field. Thus, the demand for the skillful workforce is dramatically increase.

Automation seems to be appeared to have changed the employment system, which may increase the cost of workmanship. Eventually, what benefit does ‘Automation’ to the industry? The answer is the increasing in productivity (output) and reduction of manufacturing cost, which lead to the increasing in buying power.

At last but not least, Automation not only appear in the industrial (Industrial Automation), it appear in many form such as Home Automation, Test Automation and Software Automation (also known as Macro). The OLE Automation is another form of automation developed by Microsoft Technology, which allowed information sharing and services across process and machine boundaries. As a result, you can manipulate an application’s object from outside the application. In other word, you may have multiple features such as Microsoft Word and Microsoft Excel in a single application.