Documents Software Requirements Specification

Software Requirements Specification

1 Overview

This is an example of a software requirements specification for an imagined medical device: a bedside patient monitor that continuously measures the heart rate and the blood oxygen saturation (SpO2) of one patient, raises alarms when a vital sign leaves its configured limits, and forwards the measurements to a central nurse station.

The requirements in this document are the top of the traceability chain of this demo project: architecture items in the Software Architecture Document (sad) link up to these requirements, and software units in the Software Detailed Design (sdd) link up to the architecture items.

2 Measurement Requirements

# UL DL COV DR
SRS-001 The software shall acquire the heart rate and the SpO2 value from the patient sensors at least once per second. SAD-010
SRS-002 The software shall display the current heart rate and SpO2 value on the bedside screen and shall refresh the displayed values at least once per second. SAD-011

3 Alarm Requirements

# UL DL COV DR
SRS-003 The software shall raise an alarm within 3 seconds after a measured vital sign crosses its configured alarm limit. SAD-012
SRS-004 The software shall annunciate an active alarm both visually and audibly; the audible annunciation may be paused for at most 60 seconds but shall not be permanently disabled. SAD-012

4 Data Retention Requirements

# UL DL COV DR
SRS-005 The software shall store the measured vital signs of the last 72 hours as trend data and shall preserve the stored trend data across a power loss. SAD-013

5 Connectivity Requirements

# UL DL COV DR
SRS-006 The software shall forward every measurement and every alarm event to the central nurse station over the hospital network. SAD-014
SRS-007 The software shall continue local measurement, display, and alarm annunciation without degradation while the hospital network is unavailable.

6 System Integrity Requirements

# UL DL COV DR
SRS-008 The software shall execute a self-test at every start-up and shall not enter the monitoring mode when the self-test fails.
SRS-009 The software shall record every alarm event, every settings change, and every detected fault in a persistent event log. SAD-016
SRS-010 The software shall allow changing the alarm limits only after the user has been authenticated as a clinician. SAD-016

7 Document History

Revision Description of changes Date
A Initial version 2026-07-10