CAHIMS cheat sheet

SDLC phases in order: planning, requirements analysis, design, implementation, testing, deployment, maintenance.

Requirements types: functional (what the system does) vs non-functional (performance, security, usability, availability).

Use case actors are always external to the system boundary; a use case names a goal, not a screen or step.

Data flow diagram symbols: process (circle/rounded box), data store (open rectangle), external entity (square), data flow (arrow).

Normalization: 1NF removes repeating groups; 2NF removes partial dependencies; 3NF removes transitive dependencies.

Gap analysis compares current-state and future-state workflows to identify missing capabilities or interfaces.

Traceability matrix links each requirement to design, build, and test artifacts so coverage gaps become visible.

Interface types in health IT: HL7 v2 messages, FHIR resources (RESTful), and X12 transactions for claims and eligibility.

CPOE orders are entered by clinicians; eMAR records administration events; the two are linked by the order identifier.

Five rights of medication safety: right patient, drug, dose, route, and time; barcode scanning enforces patient and drug checks.

Clinical decision support has two parts: the trigger (event or rule) and the action (alert, order set, or documentation template).

Alert fatigue rule: high override rates on an alert indicate poor specificity; tune thresholds or retire low-value alerts.

HL7 v2 uses pipe-delimited segments (MSH, PID, OBR, OBX); FHIR uses JSON/XML resources with REST verbs (GET, POST, PUT).

Terminology systems: SNOMED CT for clinical findings, LOINC for lab observations, RxNorm for medications, ICD-10 for billing.

Meaningful use / promoting interoperability stages focus on e-prescribing, health information exchange, and patient electronic access.

PHI is identifiable health data; HIPAA Security Rule covers administrative, physical, and technical safeguards, and the minimum necessary standard limits access.

Triple constraint: scope, time, and cost are interdependent; a change to one forces adjustment in the others or in quality.

Critical path is the longest duration path through the network; it sets the minimum project duration and has zero total float.

Float (slack) = late start minus early start; a task with zero float is on the critical path.

Earned value: CV = EV - AC; SV = EV - PV; CPI = EV / AC; SPI = EV / PV. CPI below 1 means over budget.

Estimate at completion: EAC = BAC / CPI when current cost performance is expected to continue.

Risk response types: avoid, mitigate, transfer, accept for threats; exploit, enhance, share, accept for opportunities.

RACI assigns each task one Accountable role; multiple accountable owners per task is an anti-pattern.

Change control: a change request is logged, impact-analyzed for scope, schedule, and cost, then approved or rejected by the change authority before baseline updates.

Go-live readiness includes user training completion, interface validation, rollback plan, and command-center staffing.