Ishikawa diagram UK /ˌɪ.ʃɪˈkɑ.wɑ ˈdaɪ.ə.ɡɹæm/US /ˌɪ.ʃiˈkɑ.wɑ ˈdaɪ.ə.ɡɹæm/ noun1 •A diagram used in quality management to display a detailed list of causes and effects of a problem and thus to decipher the root cause of a problem.The procedure for constructing an Ishikawa diagram relies on brainstorming for stimulating the QI team to think of reasons for the problem. — 2000 formsIshikawa diagrams