ITIL 4 CDS cheat sheet
ITIL 4 CDS · Keep the key ideas within reach.
Understand the concepts and challenges of creating, delivering and supporting services
Value requires both utility (fit for purpose) and warranty (fit for use); neither element alone is enough for a customer to realise outcomes.
Shift left moves testing, defect detection, knowledge capture and resolution capability closer to the point of origin; the earlier a defect is detected, the lower its cost of correction.
Swarming works an incident simultaneously with everyone who has the needed competencies; it replaces sequential tier 1 to tier 2 to tier 3 escalation when speed matters more than specialisation.
The service desk is the single point of entry for user demand; common models are centralised, local, virtual (follow-the-sun) and self-service.
Continuous integration merges code into a shared mainline frequently with automated build and test; continuous delivery keeps every build releasable; continuous deployment releases automatically to production.
DevSecOps is DevOps plus security embedded and automated at every pipeline stage, not a separate phase performed after development.
Priority rule: incident priority is derived from impact and urgency; a major incident is run by a dedicated temporary team with an agreed communication channel.
Handoffs, silos, queues and rework are the dominant structural causes of long lead times in create, deliver and support value streams.
Understand how to use ITIL practices to create, deliver and support services
Incident management restores normal service as quickly as possible; it manages the symptom and does not necessarily remove the cause.
Problem management identifies and removes causes; its outputs include known errors and documented workarounds held in the error log.
Change enablement decision rule: standard changes are pre-authorised and low risk with a predefined trigger; normal changes are assessed and authorised by a change authority; emergency changes use expedited authorisation.
Deployment moves a change into a live environment, whereas release makes it available to users; deployment can therefore occur without release (for example a dark launch).
Service request management handles predefined, low-risk, user-initiated requests from the service catalogue; it is normal service delivery, not a failure of the service.
Service level management negotiates and monitors SLAs against targets, while XLAs measure the customer's actual experience of consuming the service.
Service configuration management maintains a CMDB of configuration items and their relationships, which supports impact assessment in incident, problem and change.
Knowledge management follows the DIKW hierarchy; shift-left and self-service both depend on maintained, findable knowledge articles.
Monitoring and event management collects, filters and correlates event data so that teams detect significant events before users are impacted.
Understand how to plan and manage the flow of work and value
Little's Law: average lead time = average work in progress divided by average throughput; halving WIP at constant throughput halves lead time.
Kanban core practices: visualise the workflow, limit work in progress, manage flow, make policies explicit, implement feedback loops, improve collaboratively.
Flow efficiency (%) = active value-adding time divided by total lead time multiplied by 100; waiting time usually dominates in service workflows.
Value stream mapping records process time and waiting time for each step to expose queues, handoffs and non-value-adding activity.
Theory of constraints sequence: identify the constraint, exploit it, subordinate everything else to it, elevate it, then repeat once the constraint moves.
As utilisation approaches 100 percent, queueing delay rises non-linearly; deliberate slack protects lead time and predictability.
Where capacity is constrained, prioritise by cost of delay relative to the duration of the work item to rank delivery order.
Limit multitasking: the more items a person or team works on at once, the greater the context-switching loss and the longer each item's lead time.
Understand how to build effective teams and organisational culture
Culture is the set of shared values and the behaviours they produce; it changes through leadership modelling, explicit reinforcement and consistent metrics, not through statements alone.
Team topologies define four team types (stream-aligned, enabling, complicated-subsystem, platform) and three interaction modes (collaboration, X-as-a-service, facilitating).
Stream-aligned teams own a value stream end to end, which removes handoffs; platform teams provide self-service internal services that reduce cognitive load.
T-shaped competence is depth in one discipline plus breadth across related disciplines; it supports swarming and cross-functional flow.
Psychological safety plus blameless incident review increases the reporting of errors and therefore learning; blame suppresses disclosure.
Self-organising teams need a clear purpose, defined authority boundaries and agreed guardrails before autonomy improves outcomes.
Job demands and resources rule: burnout risk rises when sustained demands exceed available resources such as autonomy, support and feedback.
Communities of practice develop capability across silos; retrospectives and daily stand-ups are the routine feedback loops of team improvement.
Understand how to develop and manage capabilities and value streams
Capability combines people, process, technology, information and partners applied consistently; improving a value stream requires capability change, not only process change.
The four dimensions to assess for every service are organisations and people, information and technology, partners and suppliers, and value streams and processes.
Service value chain activities are plan, improve, engage, design and transition, obtain or build, and deliver and support; value streams select and sequence them.
Value stream mapping method: select the stream, map demand and steps, analyse delays and waste, design the future state, then implement and measure.
Continual improvement model questions: what is the vision, where are we now, where do we want to be, how do we get there, take action, did we get there, how do we keep momentum.
SWOT covers internal strengths and weaknesses plus external opportunities and threats; PESTLE covers political, economic, social, technological, legal and environmental factors.
Measurement rule: define critical success factors first, then KPIs that indicate progress; pair lagging outcome indicators with leading activity indicators.
Workforce and talent management maintains the right mix of skills; a skills matrix exposes gaps before they block a value stream.