Preparing for ERP, 11/02/98

Preparing for ERP
Enterprise resource planning systems call for careful - and generous - capacity estimates.

By Neal Weinberg
Network World, 11/02/98

After a year of intense network planning, Becton Dickinson next month is slated to turn on a SAP R/3 enterprise resource planning (ERP) system at the first of 180 sites worldwide. By the time it's finished, the project is expected to cost the medical products company in excess of $100 million.

Most of the investment to streamline the company's manufacturing-related business processes centers on R/3 software modules, consulting fees, training and server hardware. But Becton Dickinson is also spending between $3.5 million and $5.5 million to upgrade its LANs and WANs.

On the other hand, Brother Industries, a Bartlett, Tenn., manufacturer of typewriters and word processors, over the past year rolled out SAP R/3 after making only minor tweaks to its 150-node LAN.

That kind of disparity is not uncommon in the world of ERP because there is no standard network configuration or magic formula when it comes to making the leap to the three-tier client/server computing required for ERP systems. "There is no silver bullet answer," says David Lee, senior manager at Deloitte Consulting in New York.

But there are some best practices to follow, such as doing detailed network capacity planning prior to implementation and continuing to monitor traffic once the system is up and running. There are also certain technologies ERP implementers seem to favor, including switched Ethernet to the desktop, frame relay on the WAN and either ATM or Fast/Gigabit Ethernet in the data center. And there's a major pitfall to avoid: underestimating the surge in traffic that an ERP rollout brings, especially on the wide area and in the data center.

Gauging capacity

In his consulting work, Lee uses a tool called OPNET Planner from the Washington, D.C. company MIL 3 to ensure the network has enough capacity to provide acceptable response times without going overboard in terms of bandwidth, especially on costly wide-area links.

Joe Huehne, IT analyst at 3M, the worldwide manufacturing firm, had just those capacity concerns. His company was considering a move to the PeopleSoft 6.0 human resources package but was worried about WAN connectivity costs.

Huehne hired Make Systems in Mountain View, Calif., to conduct some capacity planning. Using Make Systems' NetMaker tool, Annette Clewett, senior network consultant at the company, first did a baseline analysis of six WAN links and discovered about half the available WAN bandwidth was being used by other applications.

Clewett then brought several 3M employees into a test lab and, using a delay simulation tool, had them determine how many milliseconds of delay were acceptable when they called up the PeopleSoft application.

Armed with that information, Clewett determined that each user would require 20K bit/sec of bandwidth in order to access the PeopleSoft application within an acceptable response time. Keeping in mind only half the capacity of the WAN links was available, Clewett calculated that a 64K circuit could barely support two concurrent users, and a 128K bit/sec pipe could only accommodate three users at a time.

Faced with the prospect of upgrading more than 100 WAN circuits, 3M decided instead to move to Version 7.5 of the PeopleSoft software. Version 6.0 is two-tier, which means each client talks directly to the database, creating a heavy traffic flow out to the desktop. Version 7.5's three-tier design significantly reduces WAN bandwidth needs because the application server, which sits between the database server and the end user, serves as a buffer.

For example, to enter an order into the system, an end user requests the application from the application server, which sends out a blank form to the desktop that simply needs to be completed. The database server is not involved at all. Sending the completed form back to the application server likewise requires minimal bandwidth and doesn't involve the database server. The heavy-duty traffic flows between multiple application servers and the central database as they shuttle data back and forth to complete the transaction.

Prepare for the deluge

Network managers who have gone through an ERP rollout agree that capacity planning, either using their own best estimates or in conjunction with consultants or vendors, is important. But they add that all the upfront planning in the world may not prepare you for the flood of traffic that can occur after an ERP rollout.

The flood is not due to the ERP applications themselves. In fact, an ERP implementation may require no additional bandwidth. A desktop-to-application server transaction under SAP R/3 generates only a 1.5K to 2K bit packet, says Tony Alfano, a vice president in SAP's professional services organization. An example would be a screen that contains a billing or inventory form that the end user fills out and sends back to the application server.

Browning Ferris Industries (BFI), which is undergoing a massive SAP R/3 rollout, found the SAP application didn't tax the network any more than green screen terminal-to-mainframe transactions.

But BFI also found that "the SAP component is the smallest piece of the pie,'' says Tom Veronie, the company's manager of telecom and equipment services. A move from the mainframe world of terminals to the client/server arena of PCs meant users for the first time had office automation software,e-mail and Internet access.

Now when a BFI employee working on an SAP screen hits the help button, it launches a browser which connects the user to a Web server in Houston. From there, the user can access self-help screens or training courses, Veronie says. Trying to anticipate that type of demand is difficult.

Because the whole point of an ERP system is to integrate all business processes onto one database, employees who may have been on different systems or on no system at all are now connected. That means an explosion of file transfers and attachment-laden e-mails in quantities that are virtually impossible to predict. "Those are the things that are scary from a WAN perspective," Veronie says.

Fighting back with infrastructure

In its 500 remote offices, BFI traditionally used shared 10M bit/sec Ethernet LANs, while the 1,000 users at corporate headquarters in Houston are connected via 16M bit/sec token ring. So far, Veronie has installed Ethernet switches at 50 of the largest branch offices, allowing him to upgrade from shared to switched connections "as soon as the capacity is threatened on any particular segment." Veronie has Remote Monitoring and RMON2 probes on every LAN segment in those remote offices to gauge capacity.

The plan is to eventually migrate all remote and headquarters users to switched Ethernet desktops, which should provide performance and reliability gains. Plus, it's cheaper and easier to support and maintain dedicated links rather than shared connections, Veronie says.

For the wide area, Veronie was forced to abandon his private multipoint SNA network because it would not support IP, which is required under SAP R/3. Instead, he went with 56K bit/sec frame relay links to 500 remote locations, using multiprotocol routers to wrap the SNA traffic in IP.

But the onslaught of WAN traffic was much greater than anticipated at some locations, so Veronie had to scramble to upgrade the 200 busiest sites to 128K or 256K bit/sec connections. The result has been "subsecond response times," he says.

Phil Freyer, director of global network architecture at Becton Dickinson, hired outside consultants to help determine his network needs. He also interviewed other SAP customers and heard the familiar refrain: ERP systems and their accompanying applications "breed usage of the network."

In light of those warnings, Becton Dickinson, based in Franklin Lakes, N.J., decided to replace its hodgepodge of 4M and 16M shared token ring and 10M bit/sec shared Ethernet LANs. The company will outfit 7,000 to 10,000 desktops with 10/100M bit/sec switched Ethernet links, which Freyer expects will provide enough bandwidth to handle the ERP rollout, along with browser-based and multimedia applications he may implement in the future.

On the wide-area side, Freyer says his 50 U.S. sites are in pretty good shape, but he faces the challenge of connecting 130 sites outside of the U.S. that have a variety of remote access setups. Many of these offices have "done their own thing over time," signing deals with local telephone companies.

Freyer's task is to migrate those sites to frame relay. He figures it will cost about $1.5 million in capital expenses to get the 130 sites up to speed and to create a dial backup system - a requirement because mission-critical information will be flowing over those links. And the $1.5 million doesn't cover recurring monthly expenses, which Freyer hasn't nailed down yet.

Becton Dickinson's plan is to provide small sales offices with 64K bit/sec frame relay, or possibly ISDN; mid-size offices with fractional T-1s; and large manufacturing sites with T-1s or higher. Traffic from all sites will feed into dual DS-3 lines in the data center.

By contrast, Brother Industries found it didn't need a major upgrade to its shared 10M bit/sec Ethernet LAN when it rolled out R/3, says system analyst John McBride. In fact, one year into the SAP rollout, McBride puts his network utilization at about 10%. The only change he made was to add Cisco LAN switches, which allow him to prioritize mission-critical SAP traffic above Internet and e-mail transmissions and to segment the network so power users can get more bandwidth than infrequent users.

McBride says he keeps tabs on network activity using Hewlett-Packard OpenView, which allows him to trace heavy network usage back to a particular desktop. He then matches up the bandwidth usage with the person's function within the company to catch any anomalies. For example, an engineer could be expected to use significant bandwidth, but if the culprit is a receptionist, he'll investigate to see whether the network is being used inappropriately.

While the ability to ration bandwidth is nice to have, for now McBride says his 10M bit/sec Ether-net LAN has plenty of capacity to run SAP and all other applications, giving him no reason to monitor the usage rate of particular applications.

In the data center

While LAN and WAN requirements may vary from company to company, every ERP implementation requires the creation of a new backbone network that links multiple servers in the data center. The data center connectivity options are ATM, FDDI or Fast/Gigabit Ethernet.

A typical data center might include the main transaction processing database server, a backup for disaster recovery, a server for developing new applications, a server for testing, and multiple application servers.

In addition, once business units within the company realize all this data is sitting in a single logical database, they put in requests for separate tracking and reporting systems specific to their needs. That often leads to new data center servers.

Bay Networks (now part of Nortel Networks) installed SAP R/3 in 1996, and now has 200G bytes of ERP information stored on its main database server. Between live backups, online reporting systems and a variety of testing and development projects, the entire database has been replicated on an additional 10 servers in the data center, according to Pierre Pellissier, corporate network manager at the Santa Clara, Calif., company.

Additionally, subsets ranging in size from 20G to 50G bytes are replicated on 10 other servers to supply raw data for various downstream reporting and data analysis systems. These servers all live in the data center and the data is updated several times per week.

Pellissier says application development people come to him just about every quarter with a new reporting system that requires support from his group. "I don't think anybody, when we rolled out SAP, would have predicted where we were going to be in a couple of years in terms of the numbers of reporting systems," he says.

"It's not just a database server and some application servers and away we go. The reality is that you're going to want to use that data in different ways that SAP doesn't natively support, so you'll probably spin out information warehouse environments or reporting environments," Pellissier says. "All of that translates into infrastructure; more hardware, more networks, more backup time, more systems analysts to support it."

Originally, Bay used FDDI in its data center, but quickly maxed out on the 100M bit/sec technology. The company now runs Gigabit Ethernet from the database server to the backup server, which has cut backup time by a third. And it runs 100M bit/sec Ethernet from the main database server to the other data center servers.

Storage Technology (StorageTek) has a similar SAP R/3 implementation story. It started with FDDI in the data center backbone, then upgraded to ATM for increased throughput and better response time, says IT architect Gary Osburn. "The warning I would give people is that traffic between application servers and the database server is more than we expected," he says.

Osburn adds that once the bugs were worked out, ATM proved to be robust and reliable. But if he had to do it all over again he would probably go with Gigabit Ethernet. "It would allow us to reuse skills we had already built up." There was a steep learning curve with ATM, he says.

StorageTek has a total of 29 servers in the data center, including one central database server, eight applications servers and a variety of backup, training, development and testing servers.

Worth the trouble

The managers agree that an ERP rollout is a huge undertaking, but the benefits to the company are enormous.

McBride says the SAP system brought more structured business processes to Brother Industries, increasing the availability of information and enabling the company to track and forecast as it never could before.

BFI, which has just completed its rollout, spent $15 million on PCs, servers, hubs, routers, cabling and other network gear. In addition, the company had to beef up its help desk and conduct a massive training program.

But the company now has a standardized way of gathering and analyzing information. "It actually works. We're somewhat surprised," says Veronie candidly. "If you plan, and you're absolutely loyal to the standards, and the whole organization has the discipline to follow suit, then you can successfully do it."

As Freyer of Becton Dickinson wraps up the planning phase and moves toward implementation, crunch time is approaching. "We feel the pressure, but we feel like we know what we're doing," he says.