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ERP (Enterprise resource planning) needs a very deep planning. You can’t design an ERP system in months. You should plan every part deeply step by step. System contains all things; network, software, hardware, education, phone and all departments’ information. You should improve this system with a team because all departments need different knowledge.

Now think about a company which one is a mail order company. This company has 15 staff. Suppose ERP software is a packet program and it is ready but you have to initialize the system. Now let’s look at ERP software and its hardware requirements.

ERP software needs a central database. And each department will connect this database by a network. Normally ERP software has these (picture 1) modules. But in this company finance, sales, purchase, inventory and logistics are enough. To make a central database we need a database server and a network.

Picture 1

Each department needs a different interface so each department’s educations and technical problems will be different. At that point we will need a training program. But after training problems will continue so there must be a technical department. I think remote support is the best one. Because it’s a small company and I think just one technical person will be working. With remote support he can instantly help any person with remote control software.

Now let’s begin from database server. Because of being a mail order company we will work with computers. Our job is completely with computers. So database is the most important thing in this system. Oracle is the best database but it depends with ERP software. You can use mysql, postgresql, mssql or firebird. Anyway we need a server. This server must work all time. There must be a backup server and on a disaster situation this backup server automatically should be the main server because in this company seconds are very important.

How can we make a self recovering system?
Personally I advise virtual systems. With these virtual software platforms you can run many computers in a physical machine. It is economical and energy saver. But the big advantage is easy back up. You can move this machine to another machine just copying virtual machine’s files. You can backup all the system while working and on any bad situation you can turn back a backup date. It doesn’t matter if it has different hardware or not. To make a self-recovering system we should write a little script. That will be working on a dns server. If the main server gets down it automatically changes the server’s ip address to backup server ip from dns records. At that point we should separate the dns server from other servers so in a disaster it will be working. Two servers backup and main should work in data synchronization. All changes in the main server should be on the backup server. And backups should be on two different disks of two servers.

Main Server Virtual Structure

Main Server Virtual Network

For servers and firewall which parts do we need?

For firewall system we have two different options like hardware firewalls and software firewalls. Simply on hardware firewall you have to spend lots of money but if you use software firewall it is so cheap. I advice one of two different open source firewalls. I am using Endian. It is a UNIX based firewall OS. And there is another project named PFSense. These are very useful and completely configurable and free.

For servers we don’t need many machines because we will use a virtual platform. You can find some information from VMware and virtualbox. We will need a main server and a backup server. We will need a fast machine. Let’s look for needed parts.

• CPU: Today Intel’s xeon processors are for servers and very good with their performances.
• RAM: We have to install as much as possible between 8gb and 4gb because we will run 5 different virtual machines on that server. So it is extremely important.
• Storage unit: Storage devices are so cheap today and I think for that project we will need about 40 GB space but buying a 500 GB device should be better for future. But our system will need performance for mostly sql. At that point it is really important for accessing data. I strongly recommend raid disks. With raid arrays you can speed your system up effectively. And if it is possible try to use network attached storage (NAS). So you will separate your storage unit from server and managing becomes easier with different backup options.
  

  10000RPM SCSI HDD

• Motherboard: We will need a special server main board for xeon processors. Today we can use Intel’s S5000 motherboard series.
• Network card: You will need at least 5 gigabit Ethernet cards on this server. Each virtual machine will need a new network card.
• Cooling system: We have to use a very good cooling system because this server will heat a lot. Usually servers need a rack. I think it’s the best way to put all these equipments in a rack.
• Power supply: We will need an online uninterruptible power supply. So on any electrical problems system will continue to work.Power supply: We will need an online uninterruptible power supply. So on any electrical problems system will continue to work.

Rack Servers - Istanbul Cebit Fair Zyxel Stand - Baran Kaynak

Rack Server

We will need two same servers on different locations. And we will need a standard pc for firewall and dns server. On any disaster they will automatically route the system to the backup server.

We will contact with warehouses which ones are outside the town. All information must be secured. Otherwise hackers can change orders. Private networks will be very secure but they are very expensive so we should use internet. Securing data can be possible with VPN connections. Two sides can send and receive packets in an encrypted tunnel. So hackers can’t read or change our data.

We will be communicating with mail or phone. IP phones have many features and you can make calls with very low prices. So we should have a mail and a voip server. Customers will be ordering online from web site. So a web server with a proxy server is also needed (proxy server can cache latest locally accessed data so you can reduce traffic). At that point we will need a high speed internet connection. But it must be also secured with a firewall. Now think about all these servers. They will be running at the same time. We will set all these servers in virtual platforms so we can use them just in a server. Isn’t it economic?

Now we have servers and we need to access these servers from departments. A local area network is needed. We need a router, switch and cat5e type cables. Most of routers have dhcp servers built-in. With cabling and connecting all routers and switches we can finish this networking job.

Client Computer

Now we need computers and ip phones for each user in each department. A pc can be more compatible with an ERP system. Each user will need these parts;

• Screen: 17” LCD monitor
• Keyboard and mouse
• A case includes these parts in it;
  • Main board
    • Network adapter card (preferably gigabit)
    • Sound card
    • Display adapter card
  • Cpu: Intel (minimum dual core series) or Amd (minimum athlon x2)
  • Ram: Minimum 2 gb

Users will just use an interface to access data and mail software to read mails. So they don’t need a very fast and expensive computer. A 300-500$ pc is enough.

We need a printer for each department. Network based printers are very useful and ready to shared using.

But there will be specialized components for each department. Logistics department needs mobile based devices with barcode readers. Inventory department needs a wireless barcode reader and writer to record all inventory in real time.

Now we need to buy IP phones to make communication easier. They are completely different from traditional analog phones. I can hear your words, “How can an IP phone be important for an ERP system? It is not about ERP!”. But you are wrong! ERP is a complete solution you have to plan everything in a company and IP phones are just a small part. Traditional phones don’t have enough features. So you can’t log any data. But with ip phones you can log every call and you can save all voice records! Now imagine that you are a worker in sales department. A customer is calling and you can see all information about that customer when the phone begins ringing. Isn’t it good? Yes this is about ERP. You can save lots of time and win lots of customers. Also there are open source projects for ip phones like Elastix, Trixbox. You can setup your own phone communication system for free! To connect pstn to the ip network we have to buy a fxo gateway, so we can convert analog lines into digital system.

Now it is time to configure all system. We have all components. The most important thing is servers. Company can serve with these computers. If they won’t work company will out of business. We have to put them in a secure place. Basement is the best place for servers. They are cold and not easy to access for people. After installing all server’s OS and ERP database we can configure the network.

On network we should configure dhcp, dns, proxy and firewall servers. Dhcp server will give an ip for each computer. Dns server will convert all addresses to ips with connecting forwarded root servers. Proxy server will make a filter for web content and it will be caching last accessed data. Firewall server will prevent us from attacks and it will make vpn connections with other remote offices. It is very important to create a rule for vpn ports. Just allow remote offices ips otherwise some hackers can make attacks. It should be better if we don’t allow pinging, so we can prevent our system from denial of service attacks. Just allow web ports for anonymous connections. So they can only connect to the web server to access web page.

Wireless network will be used for wireless equipments like mobile barcode readers, notebooks and mobile terminals. We have to create a secure connection with WPA2. It is important to choosing WPA2 protocol. Today WEP keys can easily crack. Put a MAC filter to the access points so just allowed devices can connect to the network.

We have to make a connection with our bank to get payments by credit cards. Banks can give an account for e-payments and you can access online to the pos page. Also we need to make a secure connection over ssl protocol.

At the end of this document you will see a schema of all system. In each department each staff has a computer. At first there may me some problems because of software or hardware but it can easily resolve. If it is because of software ERP developers should solve it in a short time. So you should put an entry about problem solving speed to the contract. If it is hardware problems, you should check the server and then clients. If your system contains any windows OS be sure that an antivirus software has installed. I advise you to choose Linux OS with a java based ERP software. There should be a inadequate hardware. Try to upgrade if the problems is about it. After checking all machines if problems are continuing you should check the network. If there is slowness you should find the narrow pass. Mostly slowness problems are because of bad configured routers or cheap switches. Try to fix those problems. Don’t buy a cheap switch! On these days gigabit switches and routers are very good and their prices are reasonable.

At the end please be sure equipments quality. Cheap equipments can look attractive but don’t forget they are not quality so their usage time is very short. Don’t forget these words;”I’m not rich, to buy cheap things!“.