Learn in the textbookSchedule Planning and the Arrow Diagram
DefinitionA matrix diagram (マトリックス図) lists two sets of elements as rows and columns and marks each cell where they cross with a symbol for whether and how strongly they relate, organizing how the two sets correspond.
ExplanationBecause one set of elements runs down the row headings and the other across the column headings, you can survey every combination without missing any. Each cell gets a symbol such as ◎ (strong relationship), ○ (related), or － (unrelated), which helps you spot strongly related and unrelated combinations. Like the arrow diagram, it is counted among the seven new QC tools.
AnalogyIt is like a duty roster. With names down the side and chores across the top, circling the cells each person covers shows at a glance who does what and which chores have no one assigned.
Memory hookMatrix is the same word as in mathematics. Just as an entry in a matrix is identified by its row and column, the position of a cell itself stands for one combination.