ɹˈɪtʃɚd kɹˈɔsmən dɪvˈɛləpt ɐ fˈɔːɹmjʊlə bˈeɪst ˌɔn pˌɑːpjʊlˈeɪʃən, bˈɛdz ænd kˈeɪsᵻz bˌʌt ɪts fˌʌndəmˈɛntəl pɹˈɑːbləm wʌz ðætðə fˈɔːɹmjʊlə wʌz pˈɑːɹtli bˈeɪst ˌɔn jˌuːɾɪləzˈeɪʃən ænd kˈɜːɹənt ɹᵻsˈoːɹsᵻz.
Richard Crossman developed a formula based on population, beds and cases but its fundamental problem was that the formula was partly based on utilisation and current resources.