Engineering Process & Methodology

Potentially releasable means the increment is finished to the team's shared completion standard and could ship as it stands, with no hidden integration, testing or change-review work left. Whether the business chooses to release it is a separate decision.

A stand-up drifts into a status report when the audience becomes a manager instead of the team. Reporting then replaces re-planning: nobody adjusts the day, blockers surface late, and the meeting stops changing what anyone actually does.

The right-hand items still have value — the Manifesto says only that the left-hand items are valued more when the two compete. It is a ranking under tension, not a licence to drop documentation, plans, contracts or process.

Waterfall finishes each phase — requirements, design, build, test — before the next starts, so working software and real feedback arrive near the end. Iterative delivery ships a small usable slice repeatedly, so feedback and change land inside every iteration.

Each adds a different amount of structure over one shared product. Nexus is a thin integration layer; LeSS keeps one product backlog with broad teams; Scrum@Scale grows by repeating the pattern; SAFe adds big-room planning and long-lived team groupings.

Scrum defines three artifacts: the Product Backlog, committed to the Product Goal; the Sprint Backlog, committed to the Sprint Goal; and the Increment, committed to the Definition of Done. Each commitment states what its artifact is for.

A user story is a short, user-facing description of a wanted change, written as who wants it, what they want to do, and why. The shape is a placeholder for a conversation, not a finished specification.

Scrum defines five events: the Sprint, which contains the other four, plus Sprint Planning, the Daily Scrum, the Sprint Review and the Sprint Retrospective. Each is a fixed opportunity to inspect something and adapt something as a result.

The Definition of Done is one shared quality standard that all work must meet before it counts as finished. The Scrum Team creates it; where the organisation sets a minimum standard, the team may only strengthen it, never weaken it.

Story points size an item relative to other items, folding complexity, effort and uncertainty into one number on that team's own scale. Hours invite false precision, vary with whoever picks the item up, and turn a shared forecast into an individual promise.

Kanban is applied on top of the process a team already runs rather than replacing it. You model the current workflow, make it visible on a flow board, and only then change it in small reversible steps.

Lead time starts when a request is accepted and stops when the item is delivered; cycle time starts later, when the team begins work, and stops at the same delivery. Lead time is the requester's wait; cycle time is the team's turnaround.

Pull means a stage starts a new item only when it has free capacity, and takes the item itself. Push means an upstream stage or a schedule hands work down regardless of whether the receiver has room.

A work-in-progress limit is a hard cap on how many cards a board column may hold at once. When the column is full no card may enter until one leaves, which pushes the team to finish before starting.

Trace an item that actually shipped and write down every state it passed through, including the states where nothing was happening to it. Give the waiting states their own columns; otherwise waiting hides inside the activity columns.

A branch stores nothing but a reference to one commit — a name that advances as you record work. Creating one writes a single tiny reference and copies no file content, so it is effectively instant.

The staging area holds an explicit selection of what the next commit will contain, so you can record one logical change out of a messy working copy instead of committing everything you happen to have edited.

A merge reports a conflict when both lines of history changed the same region of a file since their common ancestor. Changes in different regions combine automatically; two different changes to one region leave the algorithm no basis to choose.

A clone copies the entire history and every stored object, not just the newest files, so the copy is a working repository on its own — you can record changes, read history and switch lines of development with no server.

A tag names one exact commit in history and is meant never to move again; a branch is a pointer that advances to each new commit on its line. Re-pointing a released tag silently changes what consumers rebuild.

A decision node chooses exactly one outgoing path, selected by guards on its edges; a fork node starts every outgoing path at once as concurrent flows. A merge node reunites the alternatives; a join node waits for all the concurrent flows.

A class box stacks three compartments: the class name on top, the attributes in the middle, the operations at the bottom. A leading +, -, # or ~ on a member marks it public, private, protected or package-visible.

A lifeline is one participant in the interaction — an object, component or actor — drawn as a labelled box above a dashed vertical line down which time runs. The activation bar marks the stretch where that participant is actively executing.

A state is a named condition the object waits in over time. An event is a discrete occurrence the object perceives. A transition is the arc that fires when that event arrives and moves the object from one state to another.

Structural UML diagrams show what a system is made of — its parts and how they are arranged, frozen in time. Behavioural UML diagrams show what it does — how the parts act, react and change as time passes.