Ops & Bus Services Interview Prep (Process Improvement)

Lean

A method for removing waste (any step that uses time or effort without adding value for the customer).

Lean wastes (the 8)

Waiting, defects (errors and rework), overprocessing (extra steps), overproduction (more than needed), excess inventory (backlog), unnecessary motion, unnecessary transport (handoffs), unused talent.

Lean waste example in ops (3)

Waiting: a trade sits in a queue for manual review. Defects: a booking error that forces rework. Overprocessing: checking the same data in three systems.

DMAIC

Six Sigma's problem-solving cycle: Define, Measure, Analyze, Improve, Control.

DMAIC: what each step does

Define the problem and goal. Measure current performance. Analyze root causes. Improve by testing and implementing fixes. Control by monitoring so the gains last.

SIPOC

A high-level process map: Suppliers, Inputs, Process, Outputs, Customers. Used at the start to set the scope.

Swimlane diagram

A process map with a lane for each team or role, showing who does each step and where handoffs happen. Good for spotting delays between teams.

5 Whys

Ask "why?" repeatedly (about five times) to get from a symptom to the root cause.

Fishbone diagram

A cause-and-effect diagram that sorts possible causes into categories (people, process, systems, data) to brainstorm root causes.

Pareto

The idea that a small share of causes (often about 20%) drives most of the problems (about 80%). Rank causes by frequency and fix the biggest ones first.

Impact vs effort matrix

A 2x2 for prioritizing fixes. High impact and low effort ("quick wins") go first, and low impact and high effort go last.

Change lifecycle

Identify the problem → business case → requirements → design → build → test (SIT/UAT) → deploy (go-live) → post-implementation review and benefits tracking.

Waterfall vs. Agile

Waterfall: sequential phases with fixed scope, suited to firm deadlines like regulatory changes. Agile: short iterative sprints that adapt as you go, suited to tools and products where needs evolve.

SIT vs. UAT

SIT (system integration testing): checks that systems work together correctly. UAT (user acceptance testing): the business users confirm it meets their needs before go-live.

RAID log / RACI

RAID: a log of Risks, Assumptions, Issues, and Dependencies. RACI: a chart of who is Responsible, Accountable, Consulted, and Informed for each task.

Benefits realization

Defining success measures (such as fail rate or turnaround time) before a change, then measuring afterward to show it delivered value.

Where would you use each of these concepts for a slow manual process?

Map with SIPOC, find the biggest causes with Pareto, dig into them with 5 Whys, prioritize fixes with impact vs. effort.