PERTの大前提
https://gyazo.com/f8a934b92d1d0772dc7def8e0b0af4b9
https://gyazo.com/84c679e7bda97ab308da4b6dcdde5659
https://gyazo.com/37c6aa8b2451baba28dd8eea0ea8adc3
https://gyazo.com/8a55782b2e84241c1de9af9ef3ea8be7
https://gyazo.com/f51cab157655faf743af7834a44a8cac
https://gyazo.com/19ad44c785f8b985f521f1d18b99d2c5
https://gyazo.com/048f83fb7765db0324260765804102fb
https://gyazo.com/91e70b474a4cbed55d72141f30896bb8
https://gyazo.com/8483878d3ccf8abdb11d1d1fba4096d4
https://gyazo.com/7991f4e08846212b210d1d4bd32cbfb5