Harnessing the power of IBM System z and SAP for Retail at dm-drogerie markt

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Headquartered in Karlsruhe, dm-drogerie markt GmbH + Co. KG (dm-drogerie markt) is one of Germany’s leading pharmacy and health and beauty retail chains, with annual revenues of more than four billion Euros and a network of 2,000 stores. The company employs 17,000 people in Germany, with a further 10,000 in Austria and other Central European countries. Its subsidiary, FILIADATA GmbH, provides IT services for the company.

Like many retailers, dm-drogerie markt relies on the SAP for Retail solution portfolio to manage business-critical financial, logistics and human resources processes, as well as interfacing with point-of-sale (POS) systems in the stores. Since the initial implementation, the company has introduced numerous additional SAP applications, including SAP Supply Chain Management, SAP Solution Manager, and the SAP NetWeaver Business Intelligence component.

“SAP for Retail is at the heart of our business and we are constantly enhancing and extending the environment,” says Christian Stäblein, IT Production Manager at FILIADATA GmbH. “As the landscape evolved, we found that our hardware requirements were increasing. In order to keep upgrading and adding applications and functionalities, we needed to invest in new infrastructure capable of meeting our needs.”

Supporting major upgrades

The company planned to update all its SAP applications, including moving to SAP ERP 6.0. It also has a long-term aim to integrate its POS systems more closely into the SAP for Retail environment. To support these plans, dm-drogerie markt decided to replace its existing IBM System z 900 mainframes with a pair of System z9 Enterprise Class (EC) machines. These would run the DB2 database platform to support the SAP applications under IBM z/OS, while the applications themselves run under IBM AIX on IBM Power Systems servers.

“We have a lot of in-house experience with both the System z and Power Systems platforms, so it was natural for us to consider these solutions when we evaluated the new requirements,” explains Christian Stäblein. “We believe in giving our teams a lot of input into the decision-making process, so that they reach a high level of identification with the solution that is ultimately chosen and implemented.”

Innovative implementation methodology

The dm-drogerie markt team came up with an innovative way to perform the z9 hardware upgrade without causing any downtime in the SAP application environment. All workload was transferred onto one of the existing z900 mainframes, while the other was switched off and decommissioned. Next, one of the new z9 EC machines was set up and configured to run in parallel with the remaining z900. All the workload was then transferred to the new z9 EC, while the remaining z900 was taken offline and replaced with the second z9 EC.

Customers running SAP software on System z are accustomed to performing hardware upgrades while keeping their applications online, but the movement of the database from one hardware box to the other while the connected SAP system is up and running provides a completely new level of service.

“We consulted IBM Global Technology Services about our implementation plan, and the IBM team was very enthusiastic and really helped us to make it work,” comments Christian Stäblein. “Naturally there were a few issues, but we worked with IBM to resolve them quickly. Overall, the migration was very successful – there was no downtime or impact on user productivity. In fact, the IBM team said that they might consider using this upgrade methodology with their other customers, too.”

The dm-drogerie markt team has many years’ experience of the IBM System z platform, and was able to play an active part in the creation of the solution. IBM Global Technology Services provided design, implementation and optimization services, working closely with the in-house team to develop the new infrastructure to meet dm-drogerie markt’s business needs precisely.

The two new z9 EC mainframes have been installed at separate locations, 500 meters apart, to provide a recovery capability in case disaster strikes one of the data centers. Each machine is linked by FICON to an IBM System Storage DS8300 disk system, and the two environments are mirrored using IBM GDPS/PPRC HyperSwap Manager. Combining this technology with IBM Tivoli System Automation and Tivoli NetView makes it possible for dm-drogerie markt to switch from one environment to the other in case of failure, without any impact on production systems.

“The IBM System z hardware is incredibly reliable and robust, which is one of the main reasons we chose it,” explains Christian Stäblein. “Nevertheless, our SAP ERP environment is business-critical, so it would be a big mistake not to have a plan in place in case of disaster. If we ever need to fail over, all our applications and users can be transferred seamlessly from one data center to the other, and we can use the IBM On/Off Capacity on Demand feature to activate additional processors in the working mainframe to ensure that we have enough performance for the whole environment.”

The company takes a similar approach with the SAP application servers in its AIX environment; each application runs on at least two IBM Power Systems servers, distributed between the two data centers. In some cases, the applications run in virtualized logical partitions (LPARs) on p5-550 machines; in other cases, smaller standalone p5-520s are used.

Approximately 40 DB2 databases for the SAP applications (not including the SAP NetWeaver Business Intelligence environment) run on the System z mainframes, while the applications themselves run on the System p machines. The SAP Central Services (SCS) – including the enqueue and message servers – run on System z, using the UNIX System Services (USS) element of z/OS. SCS is critical for the proper functioning of the SAP environment, so the ability to leverage the highly reliable System z infrastructure with its automatic failover capabilities is a major advantage in terms of availability.

“If our central SAP instance went off-line for a day, the effects on our business would be significant – the logistics and planning for store replenishment would be affected, and it could potentially cost us a lot of money,” says Christian Stäblein. “So it is absolutely vital that we have a highly available infrastructure, and the combination of System z and Power Systems servers gives us the level of protection we need. System z is still second-to-none in terms of reliability, and IBM is good at ensuring that the advances made in mainframe technology are passed down to the mid-range Power Systems servers, so these are very good as well.”

Moving to SAP ERP 6.0

Following the completion of the hardware refresh, dm-drogerie markt performed an upgrade of its ERP applications to SAP ERP 6.0. The upgrades of the two production retail systems were completed during two weekends, with just 12 hours downtime for each system. There were no technical issues and the upgrades were completed on schedule.

“Moving from our existing version to SAP ERP 6.0 was a very smooth transition, and we easily accomplished it within the weekend maintenance periods,” says Christian Stäblein. “Now that we have the new application up and running, we are beginning to explore the new capabilities of the software,and we expect to activate many new features and achieve even better response speeds.”

Having completed this project successfully, FILIADATA now plans to renew dm-drogerie markt’s existing data warehouse environment (based on Power Systems servers, AIX and DB2) to fulfil further performance and availability demands.

Boosting performance

“The performance of the new environment is superb – even with 1,300 users in the central system and 1,400 in the store systems, we still have response times of less than 500ms, which is a distinct improvement over the previous infrastructure,” explains Christian Stäblein.

Benefits of variable pricing

Another advantage of the solution is the IBM variable pricing model. The mainframe workload is monitored, and dm-drogerie markt only pays for the resources it uses – no money is wasted on unused capacity.

Equally, the model makes it easier for the company to budget for internal projects and systems. Using z/OS Workload Manager (WLM), it is easy to find out how much capacity is used by each user, transaction and system in the SAP application environment, and therefore costs can be controlled on a very detailed level.

WLM support for SAP on user, transaction and program level is a unique feature of the IBM System z mainframe platform, enabling highly granular control and measurement of workload by continually collecting data on system resources and the work assigned to them. Through close cooperation between WLM and the applications, middleware and subsystems operating within z/OS, WLM can track a unit of work throughout the system and assign attributes that helps system administrators classify it.

Looking to the future

Upgrading to DB2 9 and introducing Unicode support is the next priority for the IT department. When the upgrade is complete, dm-drogerie markt will have the opportunity to leverage the new DB2 for z/OS Index Compression feature, in addition to normal hardware data compression. The index compression feature will reduce storage needs – and costs – by a further 30-50 per cent, on top of the 70-90 per cent that can be achieved by hardware compression for Unicode data.

Reviewing the success of the implementation to date, Christian Stäblein concludes: “The solution that we have built is perfect for our needs, and could only have been supplied by IBM. System z is a highly mature and technically sophisticated platform, and IBM is the only supplier with the expertise to unite SAP applications with mainframe technologies.

“Our philosophy is to empower our colleagues to play an active role in decision-making processes and take responsibility. In this case, it meant that the choice of hardware was prepared by the intensive cooperation of the teams responsible for this environment. So we can really offer an expert opinion that using System z and Power Systems servers to run SAP ERP and DB2 for z/OS is an excellent option, providing the high availability and performance that businesses need to operate successfully in a competitive environment.”