System Integration case studies Webcast: Questions answered
More answers about system integration case studies, the topic of a Sept. 22 Webcast, are provided by the speaker. Topics include risks, design standards, and communication protocols.
Automation and system integration are constantly evolving. The Industrial Internet of Things (IIoT) and Industrie 4.0 will have a major impact on how end users operate their plants and how they work with system integrators. When most wisely applied to automation and controls projects, system integrators are involved from project inception through completion.
Answering questions below is:
Joe Martin, president and founder of Martin Control Systems Inc. (MartinCSI), Additional answers from Martin follow below.
Question: Please elaborate on the typical risks, methodologies, and tools to use.
Joe Martin: This has become quite a science in the system integration industry. While some firms have long processes to determine risk, most just mark up their price for contingencies. Typical risks include:
- The end user cannot properly define the scope of work
- The schedule doesn't allow for equipment lead times or proper engineering
- The end user can't support the technology
- The system is not available to the system integrator when needed
- The end user has poor communication skills/habits
- The vendor has promised ease of implementation
- Lack of a system to keep track of scope creep
- Deliverables not clearly defined at the start of the project
- Final acceptance not clearly defined at the start of the project
- Post-project support terms not understood by the end user
- The end user fails to take ownership of the system.
An effective way to identify and mitigate risk is the pre-mortem method by:
- Hold a brainstorming session with project participants about all the things that could go wrong
- Focus on the issues considered show-stoppers, then narrow it down by most likely to happen
- Spend time creating solutions for averting the issues, or contingencies should they occur.
Q: Is there a standard for writing control functional descriptions? Is there a design standard for development of input/output (I/O) lists? What is the optimum way to estimate a PLC-based system comprising multiple PLCs (with average logic complexity)?
Martin: International Electrotechnical Committee (IEC) 61131 and standards developed by the organization PLCOpen are about as close as it comes to programming guidelines for standard control functions, including naming conventions. Many system integrators have developed their own standards to be used in the absence of an end user's company or department standard.
Estimating effort for PLC program development should include time for a functional description or sequence of operation for the end user's approval. Also, time for review meetings and code verification should be included. Finally, time for factory acceptance testing by the end user should be provided.
The old-school method of estimating hours relied on I/O count-discrete and analog. With today's network technologies and data-intensive logic, functionality modules seem to be a better approach.
Besides, many system integrators now have reusable code they can drop in for standard functionality, cutting programming and debug time dramatically.
Question: Please discuss system integrators as a turnkey or subcontractor.
Martin: Many system integrators think customers want turnkey work because customers are just so busy these days, they are wanting their projects done with one purchase order, one main point person, and more centralized project management. The reality is that many managers are taking a lead in factory automation selection and have become accustom to the IT purchasing model that has single party terms and conditions. Also, this approach passes the responsibility for transferring intellectual property to the system integrator.
System integrators working as subcontractors create confusion as to who the customer is. The end user and the party paying the bill are two different entities with different goals. This can be a trap for system integrators when they have to go through a third party to reach the end user.
The best situation is when a system integrator can work directly with the end user and coordinate with other project participants.
Question: How can a system integrator concept apply to an engineering project such as HVAC system modernization?
Martin: When equipment is already in place, an SI is ideal for modernization. And SIs can evaluate the existing system and engineer a solution to reuse, modify, or replace what's there. Often, SIs bring additional value because vendors and OEMs avoid customization of their products. Special modes, data collection, and feedback systems can be implemented by an SI to better fit an end user's specific application. And most SIs are not tied to a brand, so if a facility desires a specific brand of control equipment, an SI is typically in the best position to provide and implement it.
Question: How often do system integrators become involved with process control tuning or DCS integration?
Martin: Many SIs have staff well trained in loop tuning. Many employ software that may be too costly for only one end user to afford, especially if it's used only once or twice. And, SI engineers typically have seen a wide variety of process loops and may have unique experience in troubleshooting obscure issues.
DCS integration is not typically something SIs provide on a wide scale. Most DCS manufactures keep their systems closed and hold tight to implementation knowledge. These manufacturers provide integration services themselves and are the least likely of all the control vendors to train third parties on their systems. Although there are some SIs that have in-depth knowledge and capabilities, but they are few and far between.
Question: When integrating datalinks between control systems, what communications protocols are you seeing the most demand for?
Martin: The two main protocols in today's modernization project are Ethernet for Control Automation Technologies, or EtherCAT (IEC 61158) and EtherNet/IP. Out of the two, EtherNet/IP seems to be dominant in North America, probably due to the strong Rockwell market penetration. Many other control manufacturers are starting to provide EtherNet/IP connectivity, especially in those of drives.
Edited by Jack Smith, content manager, CFE Media, firstname.lastname@example.org.
Watch the related webcast "System Integration case studies" to learn more about this topic.