Performance Planning

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Define realistic goals, prioritise improvements, and align stakeholders — performance is continuous, not a one-off optimisation.

01 — Purpose

Goals over one-off optimisation

Performance planning helps teams define realistic goals, prioritise improvements, and create a shared vision over time.

Performance is rarely fixed through a single optimisation. Most projects need continuous improvement and clear targets — not a launch-week push that disappears when priorities shift.

Start with performance budgets for what good looks like, then use performance roadmaps to turn levels into phased work. On legacy platforms, see legacy website performance strategy.

02 — Principles

Why performance planning matters

Direction, prioritisation, and alignment beat reactive firefighting.

  • provides direction — teams know what “better” means
  • helps prioritise work — trade-offs become explicit
  • creates measurable goals — progress is visible
  • aligns stakeholders — product, engineering, and leadership share expectations
  • prevents unrealistic expectations — especially on legacy estates

03 — Avoid

Common planning mistakes

Perfect scores, arbitrary numbers, and metric-only thinking derail real improvement.

  • chasing perfect scores — performance is not a Lighthouse competition
  • setting arbitrary budgets — limits should follow project requirements and constraints
  • ignoring business realities — legacy platforms often need gradual improvement
  • focusing only on technical metrics — user experience and business outcomes matter too

04 — Practice

Define your performance levels

Current, target, aspirational, and best-in-class — four horizons teams can communicate clearly.

Current — where the site is today. Target — a realistic short-term objective. Aspirational — a longer-term objective requiring additional investment. Best-in-class — the level achieved by leading examples in the industry (use as reference, not a deadline for every route).

Example levels

Example performance levels for page weight, LCP, and INP
MetricCurrentTargetAspirationalBest-in-class
Page weight5 MB3 MB2 MB1 MB
LCP4.5 s3 s2.5 s2 s
INP350 ms250 ms200 ms150 ms

Planning considerations

  • business goals — what the product must achieve
  • user expectations — devices, networks, and journeys that matter
  • technical constraints — platform, CMS, and release cadence
  • available resources — people, time, and tooling
  • existing technical debt — what cannot move in one sprint

Align levels with Core Web Vitals field data and frontend observability — not lab scores alone.

05 — Close

Improve continuously

Realistic goals, regular measurement, and shared business context keep performance on the roadmap.

  • define realistic goals — current and target before aspirational
  • focus on continuous improvement — not one heroic release
  • measure progress regularly — trends beat single audits
  • align technical and business objectives — both appear in planning docs

See performance budgets, creating performance roadmaps, performance standard, and performance review checklist.

Common questions

What is performance planning?

Performance planning defines realistic current, target, and aspirational levels for metrics such as page weight and Core Web Vitals, aligned with business goals and constraints — not a one-off optimisation sprint.

How is performance planning different from performance budgets?

Budgets set measurable limits to enforce. Planning sets the levels and priorities those budgets serve — including what is achievable on legacy platforms over time.

What are common performance planning mistakes?

Chasing perfect Lighthouse scores, setting arbitrary numbers without context, ignoring business constraints, and focusing only on technical metrics instead of user and business outcomes.