Wondering what SLA, MTTR or RTO means? This glossary gathers the definitions of essential technical terms used in managed services and IT operations.
BCP (Business Continuity Plan)
Definition: An organisational and technical framework designed to maintain business operations with no or minimal interruption during a major incident. A BCP is more demanding and costly than a DRP, as it aims for zero perceptible downtime.
Objective: Immediate continuity with no perceptible outage. Typically requires active-active redundant infrastructure.
Also known as: PCA (Plan de Continuité d'Activité) in French-speaking contexts.
DRP (Disaster Recovery Plan)
Definition: A set of documented procedures enabling an organisation to resume IT operations after a major disaster (fire, flood, cyberattack, critical hardware failure). Unlike a BCP, a DRP accepts a temporary interruption of service.
Also known as: PRA (Plan de Reprise d'Activité) in French-speaking contexts.
Managed Services
Definition: The full or partial outsourcing of IT system management to a specialised provider. Managed services typically include maintenance, monitoring, security and technical support, delivered on a subscription basis with defined SLAs.
Example: An SME outsources the management of its 5 servers to an MSP for EUR 70/month/server (business hours) or EUR 150/month/server (24x7) instead of hiring a full-time system administrator.
Also known as: Infogérance in French-speaking contexts.
Monitoring
Definition: Continuous automated surveillance of IT systems to detect anomalies, measure performance and prevent failures. Monitoring tools generate alerts when predefined thresholds are exceeded.
Common metrics: CPU, RAM, disk space, bandwidth, response time, service availability, SSL certificates, error logs.
MSP (Managed Service Provider)
Definition: A company specialising in the delivery of outsourced IT services. An MSP continuously manages, maintains and secures its clients' IT infrastructure, typically for a monthly subscription fee covering monitoring, patching, backups and incident response.
Related terms: Managed services provider, outsourced IT, IT outsourcing partner.
MTTR / Resolution Time SLA (Time to Resolve)
Definition: The maximum guaranteed delay between the reporting of an incident and the restoration of the service to a functional state. The resolution time SLA is the most binding commitment as it implies the problem is actually fixed, not just acknowledged.
Note: Resolution time is always longer than response time and commands higher costs. A 1-hour resolution SLA is very aggressive and expensive.
Typical values: 4h (critical), 8h (urgent), 24h (standard), "best effort" (low priority).
Also known as: GTR (Garantie de Temps de Rétablissement) in French-speaking contexts. In ITIL, also referred to as MTTR (Mean Time to Resolve/Restore).
On-Call Support
Definition: A period during which an engineer remains reachable and available to respond to incidents, typically outside business hours (nights, weekends, public holidays). On-call engineers are alerted via paging systems such as PagerDuty.
Example: 24/7 on-call support means an engineer can be contacted and intervene at any time, including at 3 AM on a Sunday.
Also known as: Astreinte in French-speaking contexts.
See: On-call regulations in France | On-call support pricing
Operational Maintenance (Ops Maintenance)
Definition: The set of preventive and corrective actions required to keep an IT system running smoothly: OS and software updates, security patches, monitoring, proactive replacement of aging components and capacity planning.
Example: Operational maintenance of a server includes monthly security patching, disk space monitoring and proactive replacement of aging hardware components.
Also known as: MCO (Maintien en Conditions Opérationnelles) in French-speaking contexts.
RPO (Recovery Point Objective)
Definition: The maximum acceptable amount of data loss, measured in time, that an organisation can tolerate after a disaster. The RPO determines how frequently backups must be performed.
Examples:
- RPO 0: no data loss acceptable (synchronous replication)
- RPO 1h: up to 1 hour of data loss is acceptable
- RPO 24h: daily backup is sufficient
RTO (Recovery Time Objective)
Definition: The maximum acceptable duration of downtime for a system or service after a disaster. The RTO determines the recovery architecture required.
Examples:
- RTO 0: no downtime (automatic failover)
- RTO 4h: recovery within 4 hours
- RTO 24h: recovery within 1 business day
Guide: DRP/BCP with RTO/RPO | Calculate the cost of downtime
SLA (Service Level Agreement)
Definition: A formal contract or contractual annex that defines the expected service levels between a provider and its customer. An SLA typically includes response times (TTR), resolution times (MTTR), uptime guarantees and penalties for non-compliance.
Key components of an SLA: scope, support hours, response/resolution times by priority level, guaranteed uptime (99.9% = 8h45min downtime/year), penalties, exclusions.
Complete guide: SLA, SLO and SLI | Guide: Response Time, Resolution Time and SLA
TAMS (Third-Party Application Maintenance Services)
Definition: The outsourcing of business application maintenance to a third-party provider. TAMS covers bug fixes, minor enhancements and user support for a specific application (ERP, CRM, custom software).
Difference from managed services: TAMS focuses on business applications (ERP, CRM, custom software), while managed services focus on infrastructure (servers, networks, operating systems).
Also known as: TMA (Tierce Maintenance Applicative) in French-speaking contexts. Also referred to as Application Management Services (AMS).
Ticket (Ticketing)
Definition: A support request or incident report logged in an IT Service Management (ITSM) system. Each ticket has a unique identifier, a status, a priority level and a complete history of interactions.
TTR / Response Time SLA (Time to Respond)
Definition: The maximum guaranteed delay between the reporting of an incident and the start of its handling by a qualified engineer. The response time marks the moment someone begins actively working on the problem.
Important: The response time SLA does not guarantee resolution of the problem, only that work has begun. It is the resolution time (MTTR) that guarantees service restoration.
Typical values: 15 min (critical), 1h (urgent), 4h (standard), 8h (low priority).
Also known as: GTI (Garantie de Temps d'Intervention) in French-speaking contexts. Also referred to as Time to Acknowledge (TTA) or First Response Time.
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MSP: definition and complete guide
Understanding the Managed Service Provider model