Pressure
How hard is the system being challenged?
Admissions, acuity, census, procedures, and staffing constraints. Pressure is what most operational views already measure.
RUISA coherence model
Coherence under pressure
RUISA™ is a candidate operational coherence model for identifying where, and for how long, the chain that converts demand into coordinated action becomes disconnected under pressure.
What RUISA claims
A method for locating disconnection, not a new theory of workload
RUISA is not positioned as a new theory of workload, patient flow, resilience, or coordination. Its contribution is narrower: a structured operational method for locating where the relationships required to convert demand into completed action become disconnected, and how long those disconnections persist.
The model works on one closed chain: Roles ↔ Users ↔ Information ↔ Situation ↔ Actions ↔ Roles. When every link holds, demand is matched to the right role, informed by the right information, read against the real situation, and turned into timely, owned action. When a link separates, the work stalls or someone has to bridge the gap by hand, very often a nurse.
Four readings
Pressure, flow, capacity, and coherence
These are what the RUISA DOD reads side by side. Keeping them apart is the point: a unit can be busy and still coherent, and it can look ready while a specific link is separating.
Flow
Is operational work progressing or accumulating?
Whether admissions, discharges, and pending steps are moving through or building up.
Capacity
What resources are actually available?
The staff, beds, and time genuinely available to act, not the nominal numbers on a roster.
Coherence
Are the relationships needed for coordinated action still connected?
Whether the chain from roles to actions holds, regardless of how busy the unit is.
How coherence breaks
Separation and persistence
Separation is the point where a specific relationship in the chain becomes disconnected. Persistence is how long it stays that way. RUISA names five separations, one for each link.
S1 · Ownership
Roles ↔ Users
Work exists but no one is clearly connected to it, such as an admission without an assigned nurse.
S2 · Awareness
Users ↔ Information
Information exists but has not reached the person who needs to act on it.
S3 · Accuracy
Information ↔ Situation
What is recorded no longer matches what is actually happening on the unit.
S4 · Action
Situation ↔ Actions
The need is recognised, but the action that should follow does not happen.
S5 · Loop closure
Actions ↔ Roles
Actions happen without clear ownership of the result or of what comes next.
A separation closed within minutes by its proper owner is a normal part of operational life. A separation that stays open across a shift or longer is a structural signal. The hypothesised mechanism through which operational coherence deteriorates is persistent, unresolved separation under pressure.
Core stance
Three distinctions the model keeps
Most operational views collapse these into a single sense of 'busy'. RUISA treats each as a separate question.
- Delay is not automatically separation.
- Backlog is not automatically incoherence.
- Pressure is not automatically failure.
In the RUISA DOD
Why READY and WATCHING can appear together
RUISA ORI reads pressure: whether the unit can absorb incoming demand. The RUISA Operational Radar reads coherence: whether the links in the chain are holding.
RUISA ORI: READY
The unit has the capacity to take on what is coming.
Coherence: WATCHING
At the same time, a specific coordination problem may be developing: an admission without the expected assignment, a discharge step left unresolved, or an action waiting for clear ownership.
Showing both is not a contradiction. It is the distinction between a system managing pressure coherently and a system where the coordination needed to turn demand into action is beginning to separate.
Testing the model
A falsifiable hypothesis
RUISA is presented as a candidate model, so it has to be tested rather than assumed.
The hypothesis
Persistent disruption of the relationships in the RUISA chain will explain deterioration in operational readiness beyond conventional measures of census, acuity, staffing, and workload. If S1–S5 separation and its persistence add no explanatory power once those conventional variables are accounted for, the hypothesis fails.
What has been learned so far
In longitudinal operational data, one assumption was tested: that simply leaving an admission unresolved for longer would predict later deterioration. It did not do so consistently. That negative finding sharpened the model. Waiting time and backlog behave as measures of pressure, not as evidence of separation, which is why separation is now recorded and tested as its own construct.
In conversation with existing work
RUISA builds on, and is distinguished from, Relational Coordination, resilience engineering and the Functional Resonance Analysis Method, situation awareness research, and Reason's model of latent conditions. Its distinct contributions are the closed R↔U↔I↔S↔A chain as the unit of analysis, the S1–S5 separation typology, and persistence as a construct in its own right.
Read further
Beyond Census and Acuity: A Testable Model of Operational Coherence Under Pressure
Mouayad Al Mohtar · Preprints.org concept paper · 2026