Chartered IT Professional (CITP) Service Management and Operations Syllabus

Define a Problem and a Known Error in ITIL.

A Problem is a cause, or potential cause, of one or more incidents. A Known Error is a problem that has been analysed and not resolved — its root cause and (often) a workaround are documented in the Known Error Database (KEDB).

Contrast Incident Management and Problem Management goals.

Incident management restores service quickly (reactive, speed-focused, may use workarounds). Problem management identifies and eliminates root causes to prevent recurrence (reactive and proactive, analysis-focused).

How is incident Priority typically derived?

Priority = function of Impact and Urgency, usually via a matrix. Impact = size of effect on the business; Urgency = how quickly resolution is needed. $\text{Priority} = f(\text{Impact}, \text{Urgency})$.

What is a Major Incident?

An incident with the highest impact/urgency, causing significant disruption to the business. It uses a separate, accelerated procedure with tighter timescales, a dedicated major incident manager, and clear escalation.

Distinguish functional escalation from hierarchic escalation.

Functional escalation: passing an incident to a team with more specialist expertise (e.g. second/third line). Hierarchic escalation: notifying/involving more senior management for awareness or decision authority.

What is a workaround in ITIL?

A means of reducing or eliminating the impact of an incident or problem for which a full resolution is not yet available — for example a temporary fix recorded against a known error.

What is the purpose of the Service Desk practice?

To capture demand for incident resolution and service requests; it is the single point of contact (SPOC) between the service provider and users, providing communication and coordination.

Define a Service Request and the Request Fulfilment practice.

A Service Request is a request from a user for something normal and pre-defined (e.g. password reset, new equipment, information). Request fulfilment handles these via standardized, often automated, procedures separate from incidents.

Name four common service desk structures/types.

Local, Centralized, Virtual, and Follow-the-Sun (24/7 by handing off across time zones). A specialized variant is the 'expert/skilled' desk.

Distinguish an Event, an Alert, and an Incident in monitoring.

An Event is any change of state significant for management of a CI/service. An Alert is a notification that a threshold has been reached or something changed. An Incident is an unplanned interruption — not all events/alerts become incidents.

What are the three categories of events in event management?

1) Informational (logged, no action needed); 2) Warning (a threshold is approaching, action may be needed); 3) Exception (an error/abnormal condition requiring action, may trigger an incident or problem).

Differentiate active and passive monitoring.

Active monitoring polls/interrogates a CI to determine its status (e.g. health checks, synthetic transactions). Passive monitoring waits for and receives events/alerts generated by the CI itself.

What is SRE and how does it relate to operations?

Site Reliability Engineering applies software engineering to operations problems. It treats operations as a software problem, automating toil, and uses SLOs, error budgets, and blameless postmortems to balance reliability with feature velocity.

Define an SLI, SLO, and SLA in the SRE model.

SLI (Service Level Indicator): a measured metric of service behavior (e.g. latency, availability). SLO (Service Level Objective): a target value/range for an SLI. SLA: a contract with consequences if SLOs are not met.

What is an error budget and how is it calculated?

The allowable amount of unreliability before action is required. $\text{Error budget} = 1 - \text{SLO}$. For a 99.9% availability SLO, the error budget is $0.1\%$ of the period; when exhausted, releases halt to focus on reliability.

Define 'toil' in SRE.

Manual, repetitive, automatable, tactical work that scales linearly with service growth and has no enduring value. SRE aims to cap and reduce toil through automation.

What does the CALMS framework for DevOps stand for?

Culture, Automation, Lean, Measurement, and Sharing — the five pillars used to assess an organization's DevOps maturity.

Contrast a blue-green deployment with a canary release.

Blue-green: run two identical environments and switch all traffic from old (blue) to new (green) at once, enabling instant rollback. Canary: gradually route a small percentage of traffic to the new version, increasing it as confidence grows.

What do MTTR, MTBF, MTTF, and MTTA mean?

MTTR: Mean Time To Repair/Restore. MTBF: Mean Time Between Failures. MTTF: Mean Time To Failure (non-repairable). MTTA: Mean Time To Acknowledge. They are key reliability and incident metrics.

Give the formula for availability in terms of MTBF and MTTR.

$$\text{Availability} = \frac{\text{MTBF}}{\text{MTBF} + \text{MTTR}} = \frac{\text{Agreed service time} - \text{Downtime}}{\text{Agreed service time}}$$

Calculate the allowed annual downtime for 99.9% (three nines) availability.

$\text{Downtime} = (1 - 0.999) \times 365.25 \times 24 \approx 8.77$ hours per year (about 8 hours 46 minutes).

What is MTBF if a system runs 1000 hours with 5 failures and total repair time of 10 hours?

Uptime $= 1000 - 10 = 990$ hours. $\text{MTBF} = \frac{990}{5} = 198$ hours between failures.

What does the Capacity Management practice cover (its three sub-processes)?

1) Business capacity management (future demand from business plans); 2) Service capacity management (end-to-end performance of live services); 3) Component (resource) capacity management (individual CIs/resources).

State Little's Law and its use in capacity planning.

$$L = \lambda W$$ where $L$ is the average number of items in a system, $\lambda$ is the average arrival rate, and $W$ is the average time an item spends in the system. It relates throughput, concurrency, and latency.

Define throughput, latency, and utilization in performance terms.

Throughput: work completed per unit time (e.g. transactions/second). Latency: time to complete one request (response time). Utilization: fraction of a resource's capacity in use, $\rho = \frac{\lambda}{\mu}$ for arrival rate $\lambda$ and service rate $\mu$.

Why does response time rise sharply as utilization nears 100% (queueing)?

In an M/M/1 queue the mean response time is $W = \frac{1}{\mu - \lambda} = \frac{1}{\mu(1-\rho)}$, so as utilization $\rho \to 1$, $W \to \infty$. Latency grows non-linearly, which is why systems are sized to stay well below saturation.

What is the difference between vertical and horizontal scaling?

Vertical scaling (scale up): add more resources (CPU/RAM) to a single node. Horizontal scaling (scale out): add more nodes and distribute load across them, typically giving better resilience and elasticity.

What does Continual Service Improvement (CSI) aim to do, and what model does it use?

CSI continually aligns and re-aligns services to changing business needs by identifying and implementing improvements. It uses the CSI Approach / improvement model and the Deming PDCA (Plan-Do-Check-Act) cycle.

List the steps of the ITIL Continual Improvement Model.

1) What is the vision? 2) Where are we now? (baseline) 3) Where do we want to be? 4) How do we get there? 5) Take action 6) Did we get there? 7) How do we keep the momentum going?

Distinguish CSFs, KPIs, and the four types of metrics in CSI.

A CSF (Critical Success Factor) is what must happen for success; KPIs (Key Performance Indicators) measure achievement of CSFs. The four metric types are technology metrics, process metrics, service metrics, and CSI/business value metrics.