Applications for HMI, S-88 batch processes, historians and relational databases are commonly run on server-class computers. Recent advances in optimizing the use of computer processing power have been made with the use of virtual machines, commonly referred to as virtualization. Software platforms are developed whereby multiple applications can be independently run on the same computer hardware platform. Separate operating systems are allowed to run simultaneously on the same computer hardware. Hardware virtualized servers remove the dependency of the hardware from the operating system and allow multiple, separate operating systems to share common hardware. Interfacing between operating systems and the physical server hardware is handled through the Hypervisor.
Virtualizing Computer Servers can significantly reduce the number of physical computing machines needed for a manufacturing automation system. Typical reductions in physical computers are six for a traditional installation to two physical virtualized computers giving the same computing power and performance. The computer hardware cost savings in this scenario is 66 percent. Electrical power consumption is also reduced by more than half in this scenario of using virtualized computer hardware.
DATA AND EVENTS HISTORIANS
Traditional methods for recording process parameters, such as Autoclave and SIP temperatures, to meet regulatory compliance relied on paper-based circular or strip chart recorders. Maintenance of these electro-mechanical devices was always a top priority to insure their reliability, accuracy and repeatability. Each chart recorder had multiple points of mechanical failure including the ink dispenser, ink supply and pen driver mechanisms.
Today, pharmaceutical and biopharmaceutical manufacturers are eliminating chart recorders and replacing them with historians; software-based data recorders extracting process parameter values on a continuous basis from the PLC, PAC or DCS process controllers. Today’s data historians can simultaneously and continuously record tens of thousands of individual process parameter points per second. Most data historians use data compression algorithms to optimize the use of mass storage either locally or in the cloud.
To meet regulatory compliance for data security, unalterable records and audit trail, historians must be validated to the stringent requirements outlined for electronic records in Title 21 CFR Part 11. Successful implementation of process data historians meeting Part 11 requirements begins at the Validation Master Plan for Computer System Validation (CSV). A systematic approach to the software development lifecycle greatly increases the probability of successful implementation of a software-based process data historian meeting regulatory compliance. Requirement specifications must clearly identify the detailed methodologies to implement Part 11. Then the validation protocols (IQ and OQ) must have detailed test scripts, with supporting documentation, verifying that all requirements for Part 11 electronic records are met. The net result is a reliable, robust and secure data historian that usurps the need for traditional chart recorders.
Traditional methods for recording events, such as batch start time and end time or target and actual ingredient quantities, have been paper records; MBRs or Manual Batch Records. MBRs do meet regulatory compliance and are very labor intensive. The MBR’s accuracy and completeness rely entirely on the operator. Maintaining paper MBRs becomes critical for traceability of the manufacturing process.
Like the historians described above, manufacturers are moving away from the paper-based MBRs and embracing software-based event archivers and report generators. Similar to the historians, event archivers, or transaction managers, record events germane to the manufacturing process. Typical recorded events include batch start and completion times, manual ingredient additions by the operator, target and actual ingredient fill quantities, operator interventions, and audit trail information. The significant advantage to using software-based transaction managers in lieu of MBRs is the critical event data is automatically captured via the process controllers and HMIs, then stored in a relational database such as Microsoft’s SQL. Once the event data is captured, batch and other production reports can be generated.
The event archiver and reports can also be created to be compliant with Part 11 for electronic records. The probability of success of implementing Part 11 compliant reports significantly increases when the integrator/programmer gets involved early in the system development lifecycle with those responsible for meeting regulatory requirements.
Today’s requirements for process data, inter-device communications, and secure access to the process controls mandate the need to have the system design team give special attention to the networks; their physical installation and configuration to optimize data throughput and security. A variety of network types and topographies are used in manufacturing automation systems, but a Converged Plantwide Ethernet (CPwE) architecture including technologies such as EtherNet/IP and Device-Level Rings are becoming more prevalent for Industrial Automation and Control Systems (IACS) networks.
According to Cisco, “Modern, full-duplex, switched Ethernet networks offer real-time performance, including latency, jitter and packet-loss avoidance capabilities that meet or exceed the needs of IACS applications while offering better benefits than the older field-bus networks they replace. In addition, these modern networks have mature and tested technologies to safely secure the network and the systems they interconnect beyond what are available for the older field-bus networks.”¹