How to Purchase The Right Piece of Equipment?
Despite all your efforts, and following the conclusion of one of the analyses that you carried out with the Analytics tool available on Mobility Work, you have just realized that one piece of your equipment’s maintenance has become too expensive. Consequently, you have to invest in a new piece of equipment, but how to take the right decision knowing that certain investments can reach up to several million euros ?
Defining your needs
First, you have to define your needs precisely. It may seem obvious, but many projects have been delayed or cancelled because the needs had not been defined accurately. You have to choose the most appropriate new equipment which will allow you achieve what you want. For instance, in the case of a machining center, we picked 4 selection criteria, which can be divided into 4 sub-criteria:
Selected criteria: table, head tooling, environment, and availability rate
1rst criteria: Table
In this case, the table dimensions and the strokes on each axle are both essential, since they are going to define our limits regarding the size of the parts that we will be able to machine. We also took the traverse speed into account on each axle, and this information will enable us to estimate the machining time as well as the cost price of the machined parts on different selected machines.
2nd criteria: Head tooling
There are several important data about head tooling: spindle speed, approach precision, number of tools which can be integrated to the warehouse as well as their type, their weight and their maximum dimensions tolerated by the machine… these sub-criteria will enable us to make our choice. We will compare the existing machines on the market regarding productivity, but we will also compare them with our existing industrial equipment in order to standardize our tools and to optimize changeovers, like SMED (single minute exchange of die).
3rd criteria: Environment
The environmental issue is increasingly taken into account when investing in new equipment. Do the selected machines require a lot of electricity? Do they require a lot of oil?
You can find all the data relative to these first three criteria thanks to the descriptions available on Mobility Work.
4th criteria: Availability rate
When purchasing a new machine, it is essential to wonder if the machine you want to buy is reliable. First, you have the opportunity to go to see another user of this machine, and by talking with him, you will be able to make up your mind regarding its availability rate, but it is not always easy to obtain such information. Another possibility is to consult your task history available on Mobility Work CMMS. It enables you to see the intervention time spent on an equipment, to determine its critical point and its recurrent failures, as well as to anticipate a spare parts stock otherwise.
These four criteria are the most important ones according to the technical service. Other criteria can also be taken into account such as the price, the after-sales service, the certificates of conformity, etc. The relevant departments (purchasing, quality, logistics, etc.) will point out these criteria, knowing that such an investment cannot be made alone, but as a team!
Trying to find the perfect equipment!
Now that you have defined your criteria and sub-criteria, you have to rank them and weight their importance :
|Width between columns||2850||4||3000||5||4100||7||4850||10|
|Height (under top)||1400||0||1950||6||2230||8||2675||10|
|Axis X speed||10 m/min||4||25 m/mn||6||32 m/mn||8||40 m/mn||10|
|Axis Y speed||10 m/min||4||25 m/mn||6||32 m/mn||8||40 m/mn||10|
|Axis Z speed||12 m/min||4||25 m/mn||6||32 m/mn||8||30 m/mn||7|
|Spindle speed||4500 tr/mn||5||6000||10||5000||7||5000||7|
|5 axis positioned head||0,02 mm||9||0,02 mm||9||0,02 mm||9||0,01 mm||10|
|Tool tightening option||no||0||pedal||5||no||0||no||0|
|Nb tools warehouse||32||4||80||10||60||8||40||5|
|Max tool diameter||120||7||125||10||120||7||125||10|
|Max tool length||400||8||400||8||500||10||400||8|
|Max tool weight||20||8||20 kg||8||25 kg||10||20 kg||8|
|Cone type||ISO 50||10||ISO 50||10||ISO 50||10||ISO 50||10|
|Spindle engine power||30/37 Kw||10||37 Kw||10||35 Kw||7||37 Kw||10|
|Spindle engine torque||1000 N.m||4||1298 N.m||7||1005 N.m||4||1822 N.m||10|
|Spindle engine speed||0||0||0||0|
|Electricity consumption||55 KVA||8||50 KVA||10||50 KVA||10||50 KVA||10|
|Chip conveyor/X||screw (2)||4||lamellar (2)||10||belt (2)||6||lamellar (2)||10|
|Sprinkling rate||20 bar||8||17 bar||7||50 bar||10||20 bar||8|
|Lubricant tray capacity||1000||5||2000||10||2000||10||1200||6|
|Guarantee||1 year||5||5 years||10||1 year||5||1 year||5|
|After-sales service / seller||St ETIENNE||6||ALENCON||10||LYON||5||LYON||5|
|After-sales service / manufacturer||TAIWAN||2||Spain||10||Italy||7||Italy||7|
|strength||X||0||Lubricat. head||10||Width +||7||Sizing T||5|
On this table, all these criteria have been selected for our future equipment. In yellow, we can see the first criteria (table), in green the second criteria (machining head) and in blue the third one (environment). The criteria in white were defined by the other departments also involved in purchasing this new equipment.
A grade from 1 to 10 is attributed to each criterion. The maximum grade is attributed if it corresponds to the machine specifications, and the minimum one is attributed when the criterion does not correspond to the need. Of course, some criteria can be mandatory, which means that if one criteria does not conform to specifications, then the equipment cannot be retained. If you think that some criteria have to be highlighted, then they can be weighted and considered as more important than the others.
Finally, once all your criteria are marked, the sum of grades will provide you with a ranking. The higher the score, the closer to specifications.
With this method, you will integrate all the data which are essential when purchasing a new equipment from a technical point of view, but also from the point of view of your coworkers from the other departments of your company. It enables not to forget criteria which might seem less important to you and may jeopardize your machine after its arrival on site.