EC: SILAlarm

Safety: exida SILAlarm. SILAlarm is an engineering tool for optimizing alarm system design and operator response to alarms by helping determine which alarms are required (eliminating those that are not necessary), by establishing their configuration settings (priority, limit, deadband, on / off delay), by documenting the cause, consequence, and operator action, and by facilitating compliance with the ISA-18.2 standard. This is a Control Engineering 2011 Engineers' Choice (EC) Honorable Mention.

November 1, 2010

SILAlarm guides users through alarm rationalization – a systematic process for reviewing and justifying potential alarms to ensure that they meet the criteria for being an alarm and documenting their design. Rationalization is a key activity in the ISA-18.2 alarm management lifecycle and a proven alarm management technique that reduces alarm load on the operator, eliminates nuisance / redundant / false alarms, and improves operator response. The tool is flexible and easy-to-use, helping novices and experts comply with alarm management good engineering practices.

It can be configured to match the alarm design rules specified in a company’s alarm philosophy document.  SILAlarm leads users through the rationalization process prompting them to make the necessary design decisions and documenting them in a Master Alarm Database. This reduces training requirements and expands the number of personnel that can effectively use it. To ensure operators know which alarm to respond to first, SILALarm determines priority based on the alarm’s potential consequences and time to respond. It calculates alarm limit taking into account process dynamics, operating conditions and operator time to respond. For alarms identified in HAZOPs and LOPAs, it verifies that the operator response time is adequate to be an effective independent protection layer. Safety hazard and risk assessment results can be recorded to provide traceability between functional safety (IEC 61511) and alarm design.

To help operators diagnose and respond more effectively, alarm response procedures are created from the rationalization results. Advanced alarming schemes (e.g., suppression, shelving and state-based alarming) can be designed to ensure alarms are always relevant. Alarm configuration details are exchanged with control systems via import / export to MS Excel. This allows for bulk engineering and enables data to be propagated into the control system without manual entry. Productivity can be maximized via powerful filtering, status tracking, and copying features.


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