Present Perfect is used when we speak about recently competed actions ex. "She has just washed my car" or indefine past actions ex. "I've been to Paris twice" Past Simple is used when we speak about actions completed in the past when there is direct or indirect time refference. He left an hour ago. (direct) He left before the teacher came. (indirect) In answer to Your question, You can use the sentence "the book has been written" when it is recently completed action; and use the sentence "the book was written" when there is time referece, ex. "The book was written in 1994".

Past Simple Tense (Passive Voice) описывает просто факт, что (как) сделано, что (как) выполнено. The text was written in block letters = Текст был написан печатными буквами. My question was answered at once (by them) = На мой вопрос (они) сразу ответили. Perfect Present Tense (Passive Voice) употребляется в случаях, где подчеркивается завершенность действия к данному моменту. This letter has been written = Это письмо (только что) написано. Your letter has been sent off = Ваше письмо отослано (только что).