Beverage Vending Machine
Maébh Costello, Celeste Bergin, Michelle Noonan
The coffee vending machine chosen for evaluation for this project was determined to be
a good example of a product that was designed for functionality only. Due to innovations in
design areas, more innovative features must reinforce functionality. It was these aspects of
modern design that were applied in the evaluation of this project.
Before actually evaluating the project it was decided to look into how similar type
machines were designed. The study group visited several food/beverage establishments,
taxi companies, and shopping areas to make comparisons to similar products. Photographs
were taken of other vending machines to assist in the evaluation process. The next step was
to search companies with similar products on the Internet, which was successful in terms of
comparing similar usage types of machines and selection design.
By looking at a variety of vending machines a list of user-friendly features was developed.
These features include:
• Large LCD screen with good contrast between text and background
• Adequate button size for user’s fingers to make selection
• User’s preference choices near the basic selection
• Visual categorization through use of colour
• Readability of text
• Pictorial representation of product selection
• Organization of information that is simple and clear to follow
• Graphical symbols to give direction of steps
• Height level of dispenser near user’s waist that provides easy access
• Coin return does not require bending or stooping
• Minimal written directions
• Good drip system for dispenser area for spillage
The main users targeted for this study were guests to the college, students, staff, and
faculty since they are the ones most likely to use the machine to obtain a beverage. For
ergonomic and anthropometric reasons we chose a specific range of users to complete our
task analysis. A selection of users was based on height, gender, culture, and job or role (i.e.
students, office support, security, and English learners).
Initial User Observations
Initial observations were made of the users interacting with the machine’s interface. This
allowed the group to view the natural use of the machine (user oblivious to observation).
interaction with the machine interface. This process allowed the group to identify critical
stages of interaction of the machine and define requirements for a user task list.
In order for the user to receive a beverage from the vending machine he or she must
complete a series of simple tasks. They must do the following steps in order to do so:
1. Be able to find information if needed to operate machine
2. Insert coins
3. Adjust the strength of the beverage
4. Select sugar if desired
5. Press the desired selection
6. Remove change if necessary
7. Remove beverage from dispenser
Users were given has much time as needed to complete these tasks. This is to determine
the usability of using the beverage vending machine without outside assistance. It is assumed
that all the instructions that they will need will be available through the vending machine
interface. These seem like simple steps but will the design of the machine support the ease of
these straightforward tasks?
User Interaction Process
Initially users approached the unit and examined the menu possibilities. The menu system
on this machine model has not proven to be user-friendly as indicated by users who “think
aloud.” For example, the user would search the menu to determine which step to do first
– insert money, make selections, or make extra preference selections. It was also noted that
users who “think aloud” made the comment that they were not sure when the dispensing was
finished and had to “queue” to get the beverage. Difficulties with these aspects of the vending
machine add an air of confusion. This is due to a several issues:
1. Cluttered menu layout
2. Badly displayed instructions
3. Repetitive logo illustration
4. Visual mapping disorientation
5. Product feedback
6. Lack of visual consistency
7. Menu selection constraints 2
Users acknowledged via surveys that they viewed the machine as an uncomplicated
product. However, usability studies, video footage and photographic references show and
outline the product usability as poor.
Results of User Questionnaire
• 80% of users visually navigated the machine interface by mapping, affordance and
• Average user interaction time was 52 seconds.
• The most confusing aspects of the menu interface were found to be: Selection
Method, Sugar and Extra Sugar, Strength.
• The machine LDC screen was found to be ‘Useful’ by 70% of users.
• Half of all users were unaware of the pricing of each beverage.
• All users reported the company logo easier to read that the actual selection menu and
• All users said they would like a pay by notes and coin system.
• 90% of users were unaware when their beverage was ready for removal.
• Only 10% users noted the beep noise that indicated that the beverage was ready for
• A large majority of users (80%) were unhappy with the cup dispensed with the
• 70% of users reported that the hygiene of the machine would affect their purchase of a
• All surveyed stated that they could not view what was occurring in the drip tray area
of the machine, from a standing position.
• All users reported that they were unhappy with the after sale service of their machine.
Surveyed users reported the product to be average in terms of usability. Even though 80%
of users visually navigated the machine interface by mapping, affordance and memory, the
average user interaction time with the machine is 52 seconds. Evidence indicated that even
though users are previously aware of product, usage time is not very inefficient.
Video Analysis of Users
For the most part users of the beverage vending machine were able to walk away with
something to drink from the machine as indicated from the video footage. The time it took to
actually take the drink depended on their knowledge of how the machine worked, their ability
to find the information to make their selection, the type of drink selected, and in one case the
ability to understand the written language of directions.
Analyses of the video footage indicate a number of common difficulties with using the
beverage vending machine. The observed difficulties among users are:
• Ability to locate directions with ease and/or navigate visually without reading
• When to make a pre-selection, i.e. extra sugar or strength
• Feedback from the machine when it recognizes that a selection has been made by the
• Necessity of bending down or stooping to see if beverage has been dispensed
• Necessity of bending down or stooping to collect change or drink
• Careful removal of cup from dispenser due to a flimsy container
• Necessity of holding cup near the top due to heat
• Length of time for product to dispense
• Occasional malfunction of machine with no number available for assistance
• Cleanliness of dispensing area was an issue
These key points of issue with the beverage vending machine are features that can be
addressed through designing an easier user interface that can be more attractive and
Functions and Feature Analysis
The most confusing aspects of the menu interface were found to be with the selection
method, sugar and extra sugar, and strength.
1) Selection Method
The drink selection process was confusing to novice users. The user must first add
strength and sugar to the beverage before selecting a drink option as reflected in the
instructions below. This aspect of the menu confused users as they were initially
selecting a beverage first, consequently missing the opportunity to adjust their
beverage to taste.
Step 1. Insert coins
Step 2. Adjust strength if required
Step 3. Select sugar if required
Step 4. Press desired drink selection
This occurrence is mainly due to badly displayed instructions and poor menu interface
2) Sugar and Extra Sugar
The add sugar and add extra sugar options were overlooked by many users. Users
reported this to be due to a badly menu arrangement and display.
This feature was designed to allow the user to adjust their beverage selection to their
personal taste by strengthening the beverage of choice. 60% of users did not utilise
this function, as they did not know what it was.
A large majority of users surveyed revealed that they found the LCD display screen
helpful. But when quizzed about the feature in more detail, a range of difficulties were found:
• A larger is screen required
• Needs to be placed at an average eye level
• Larger visible screen text
More detailed instructions, via the display screen, are needed to guide the user through the
Menu Selection Buttons
Adult male and female anthropometrics figures do not comply with the size of the button
features on the menu. The button measurements are far too small for user-friendly usage. The
buttons in this machine were also doubled functionally as they hosted the price details of the
beverage it represented. On the menu consol area the button features were over-shadowed
considerably by company logo displays
The price list for the menu selection is positioned on the actual selection buttons, as stated
above. This listing system proved to hinder and confuse the users, as half were unaware of
pricing while using the machine. All of them in the user test had to lean towards the machine
and squint to read the price details.
It was determined that visual consistency in the text and graphic layout was poorly
designed. In terms of consumer graphic navigation, this machine rated very low. The
company logo is featured 18 times on this machine, taking up a large proportion of the
products visible surface. It proved to be a confusing element with all users tested in the
usability study. All of users reported the company logo easier to read than the actual selection
menu and prices. It is needless to say that this type of design concept is very mediocre and
hindering in the usage of the interface.
The coin slot on the machine is not explained or even sign posted. Nevertheless, users’
familiarity and memory of this payment method meant that no issues were founded here.
The spare change factor of the vending machine proved to be an issue with a large
proportion of or users. All of users said that a note payment method should be incorporated
into the machine.
The change button was not utilised by any of the testers. When quizzed about this feature
the users reported the feature as an unnecessary part in the product design. Due to the fact
that the change is automatically dispensed as soon as an option on the menu is selected.
The change indicator consists of an orange LED positioned to the left of the coin slot.
The instruction and explanation of this feature is placed directly below the coin slot. The
positioning in this case is acceptable, but the description details are very badly displayed.
The text is in a small font, coloured white on a grey background. These factors combine to
displayed bad instructions.
The coin collection point on this machine is positioned at the bottom right hand corner.
All of users were recorded bending down drastically to retrieve their change. For ergonomic
reasons small, average and tall men and women were chosen to take part in the usability
testing. This aspect proved that the coin collection point is positioned at a very impractical
The main instructions for the machine are placed to the lower left of the LCD screen
and consist of white text on a black background. The instructions themselves are easily
understandable. The instructions appear twice on the machine; however users still found them
hard to locate and use affectively.
On the instructions situated beneath the LCD screen on the unit, the information is
presented in five different languages, English, Italian, French, German and Spanish. This is
a helpful element on the machine but this is the only place other languages are used; every
other text-based aspect is presented in the English language.
Instructions for the payment method are also present. Yet these instructions only go as far
as to inform the user which coin denomination the machine accepts.
Distribution Point and Drip Tray Area
All of those surveyed revealed that they could not see what was occurring in the drip tray
area of the vending machine. This factor proved to be substantial in the evaluation of this
product, as this is one of the fundamental actions of the process involved in usability. Many
complications were incurred due to this design flaw.
When a beverage is vended it is released into a holder for the user to retrieve the hot
drink. However, due to poor visibility, users found that spillage occurs, as they have to bend
down to view what is happening in the drip tray area. All end products from these vending
machines are hot drinks; it is needless to say those spillages are harmful to the user.
Removal of Purchase
The correct way to remove the drink from the dispenser is to squeeze the plastic cup as
you pull it outwards. These instructions are not displayed anywhere on the unit. With this
factor in addition to the poor visibility issue spillages are a given.
Operation completed, 90% of users were unaware when the process was complete and
were unsure as to when to remove the drink. The machine does indicate its completion by
beeping in sequence however only 10% of our users noticed this.
Through the usability test it was noticed that when removing the cups from the distribution
area, users were holding them at the very top. This is due to the lack of correct insulation in
the plastic cups. 80% said that they would prefer a cup with a lid. Styrofoam was the most
popular cup material selection.
This beverage vending machine is restricted to vending hot drinks only. Still basic
design flaws are present within the machine distribution of these hot items. Users’ tests have
highlighted the fact that 80% of users experienced spillages while removing their selected
item from the machine. This is due to 2 basic design errors:
1) Distribution drip tray area placed too low down on the machine, disabling user to
visualise what was occurring.
2) To remove a beverage from the machine the user must first squeeze the cup
slightly to remove it from the distribution point. However this function is not
explained anywhere on the machine. The cups utilised in this vending machine are
light plastic. This cup is inadequate when dealing with hot beverages.
Although not life threatening, when dealing with hot substances certain standards must be
A high percentage of users (70%) described the drip tray area as dirty. 80% of these report
that an unhygienic and dirty machine would stop them from using it. Due to the spillage
factor (outlined above) the surrounding floor area of the machine was dirty and grubby. The
hygiene of the selection menu was also a factor. Due to the faded and unclear condition of
labels made the machine ‘look’ unsavoury.
After Sale Service
No contact information appears on the machine in the case that a problem should occur.
Users have reported that this is a very irritating factor. Many users reported that when a
problem occurs, e.g. machine steals money, their frustration is taken out on the machine.
This frustration can take the form of screaming, cursing or even physical contact (kicking the
This product is a good example of human feeling in relation to system/product usage - e.g.
one individual asked to take part in the study refused as they felt that that particular machine
‘was out to get them’. In the few times that the individual had used the machine it did not
vend the selected item or stole the money inserted into it.
A number of ergonomic issues where identified with this vending machine.
1) All the user spectrum participants had to bend down to retrieve selected beverage.
2) This bending down aspect also occurred when retrieving change from the change
3) All surveyed revealed that they could not visually see what was occurring in the
distribution area of the machine.
4) Cups were insufficient for the task of holding hot beverages as they did not protect
the user from the heat element of their selected drink.
5) User confusion led individuals to leaning and squirming in indecision and
puzzlement. This aspect can be easily viewed on the accompanying video footage for
this paper. Users bent their spines in compromising ways.
6) The insert coin facility also proved to be very un-ergonomic.
The more experienced users that took part in the usability study completed tasks from
memory. Consumers are used to vending machines having very bad user interfaces, so they
are unaware of the negative issues surrounding this product. This beverage vending machine
complies with the standard layout of conventional vending machines where the coin input
slot and menu interface are positioned at the top of the machine. The drip tray and coin
collection slot are positioned at the bottom of the unit. These facts also allow users to build a
memory of usage when using the product. Conventional designs, for example, ATM machines
and toiletry machines, allow this ‘pre-training’. This affordance of previous knowledge use is
a leading factor in users’ navigation skills on this particular vending machine.
Upon completing the data analysis of the usability of the beverage vending machine it
was concluded that a reworking of the user interface and physical characteristics would be
effective to facilitate operation. Areas of improvement would be in the organization of the 8
information needed to complete the process and the physical approximation of the dispenser
and change return. Input from the users indicated that they would prefer a different type of
cup in terms of material due to heat radiance and durability. All these ideals for the redesign
process are incorporated into the prototype proposal.
Push the technology of the product into the contemporary century. Use a large touch
screen menu to incorporate all menu possibilities:
• Menu selection
• User preferences, e.g. add sugar
• Change return
• User instructions
• Operation process indications
• Effective advertisings
• Various options for text readability e.g. increased text size options
• Various language options (consistent to whole process)
• After sale service details
• Touch screen button must be large and concise.
Product Internal Architecture
Rearrange the product architecture to allow for a complete product redesign from the
inside out. The research completed for this project depicts that the re-design of these features
are not restricted in any way. By redesigning the machine in this method, it affords a more
effective end product.
The machine must be designed with all users in mind.
1) The external interface and interaction elements for the consumer users.
2) The vending machine maintenance issue must be made user friendly for ease of
preservation and upkeep.
3) The issue of stocking up the machine with consumer products must be made
effective and efficient.
90% of individuals who are responsible for stocking revealed that the biggest vending
error factor is due to bad stocking and placement of products within the machine.
The hygiene factor proved to be a very important element to consumers. With this in mind
certain concepts must be kept in mind for the redesign. Minimal visible spilt lines and joins
on the front surface area. The less nooks and crannies there are for germs and dirt to breathe
in, the better. An effective drip tray design must be incorporated into the design as a number 9
of issues were found in this area.
The advised payment method would take both coin and paper money. All of the payment
features should be positioned at an ergonomically comfortable level. No bending involved.
The payment method instructions would be displayed on the touch screen interaction menu.
A more eco friendly cup material that has the ability to insulate the hot beverage must be
incorporated into the machine. A high percentage of users reveal that they would like a lid to
cover their beverage.
A new beverage distribution method must be integrated, one that does not hinder the user
and complies with safety standards.