Three levels, and conflating them is the most common structural fault in a
requirements document.
level answers example owned by
------------- ---------------------------- --------------------------------------------- -----------------
Business Why are we doing this at "Reduce the cost of processing a supplier Sponsor
requirement all, in terms the business invoice from £14 to under £5 by Q3."
already measures Measurable in
the business's
own numbers
Stakeholder What does a particular group "As an accounts payable clerk I need to see Named stakeholder
requirement need in order to do their which invoices are blocked and why, without group
work opening each one."
Traceable up to
a business req
Solution What must the solution do or Functional: "The system shall match an Delivery team
requirement be incoming invoice to a purchase order on
supplier ID, PO number and net amount."
Non-functional: "Matching shall complete
within 2 seconds for 95% of invoices at a
load of 8,000 invoices per hour."
Transition What is needed only to get "Twenty-two months of open invoices must be Delivery team,
requirement from as-is to to-be, then migrated and reconciled to a zero variance then retired
becomes obsolete before cutover."
The column that gets skipped is the first. A document that begins at the solution
level describes a system with no stated reason to exist, so when the budget is
challenged there is nothing to defend it with, and when two solution requirements
conflict there is no higher authority to resolve them against. "Reduce cost per
invoice to £5" settles arguments that "the system shall have a dashboard" cannot.
The transition row is the one candidates have never heard of and it is where
projects overrun. Migration, dual running, reconciliation, training and
decommissioning are real work with real requirements, and because they do not
appear in the target-state specification they are routinely discovered in the last
month. Naming the category unprompted is a strong signal.
The ownership column is the practical use of the model. Each level has a different
person who can approve a change to it, so a request that alters a business
requirement cannot be waved through by a delivery team, and a solution detail does
not need a steering committee. Most change-control disputes are really disputes
about which level was affected.