1. ANALYSING

1.1. Product investigation
        

32 arena chair systems were analysed through the following variables:

•    Functionality
•    Human factors
•    Comfort, dimensions and information
•    Materials and processes
•    Safety
•    Installation
•    Fixtures (tread, riser, beam mounted, low down, matrix)
•    Aesthetics
•    Cleanability
•    Sustainability
•    Cost


There was a group of questions under each variable used in the analysis. The 3 issues below where selected as the macro problems to solved.

a. Sustainability
Different from other sustainable designs, we wanted it to be economically viable. Maybe it’s one of the most difficult things.

b. Aesthetics
All the designs are clearly conceived as regular chairs. We decided it must be designed as sport equipment, which would extend the whole experience of watching any sport event.

3. Safety
Many things must be analysed under this variable. One big step was the change of the tip-up system from gravity to spring working, increasing the width of each row between seats.

1.2. User studies
Unstructured interviews and pictures were taken. It seemed that nothing similar as done before. Amongst the present systems available in the market and studied by us none clearly stated any user studies and most have very basic mistakes like having all the information about seat position and numbering covered by the users when seated.

Figure 2: Energy consumption in each period of the life of this products.

1.3.2. Lifetime of each part

One basic issue in sustainable designs is to try to achieve a common lifetime for all parts, avoiding the waste of energy and natural resources. We could not find this concern in any of the chair systems studied. Because of many different reasons we must manufacture the seat and back parts in polymer resins. So we decided to adopt a universal structure that lasts dozens of years and exchangeable sear and back parts.

Figure 3: The difference between Recycling and Extending the product’s lifespan. 

2. DEVELOPMENT
2.1. Business Model

2.1.1. Supplier
Leases the structure and sells the back and seat parts in different shapes with universal fixture. He has the responsibility to maintain the system working, especially because it belongs to himself.

2.1.2. Client 
Can afford a high quality system with low initial investment buying just the back and seat. The arena administration can be sure its seats are well maintained as the supplier is the one who is going to worry about it. 

2.2. Design Process
Here can be seen the studies made to ensure that the chair will be comfortable in nearly all positions it can be installed

2.3. Dimensioning
One of the most difficult things was to give the right dimensions to the universal leg parts. We must be sure it will place the seat between the maximum and minimum ergonomically recommended gap at the most common situations. The increase of a few millimetres in one part could affect the height of all the assembly.

2.4. Materials and Processes
We sought from the beginning to determine mass production processes in order to achieve a low manufacture cost for all the assembly. There is a centre die-casting steel gear, there are aluminium plate stamped parts and a system of male and female screws that closes the system.

3. CONCLUSION
We end up with a system designed with knowledge gathered from the users and for a market that needs cost efficient solutions, but adapted to the international standards of quality and safety.