問53
頻出度★★★
50本のプログラム開発を A 社又は B 社に委託することにした。開発期間が短い会社と開発コストが低い会社の組合せはどれか。 〔前提〕 ・A社 生産性: プログラム1本を2日で作成 コスト: 4万円/日 ・B社 生産性: プログラム1本を3日で作成 コスト: 3万円/日 ・プログラムは1本ずつ順に作成する。
平成31年度 春期 ITパスポート試験 問53
マネジメント系システム開発技術 › システム開発技術
This question's explanation and your answers so far.
解説
問 53
- ア
正解 Since the 50 programs are made one at a time in sequence, the development period is found by 'number of programs × days per program', and the development cost by 'period (days) × cost per day'. Company A takes 2 days per program, so its period is 50×2 = 100 days and its cost is 100 days × 40,000 yen = 4,000,000 yen. Company B takes 3 days per program, so its period is 50×3 = 150 days and its cost is 150 days × 30,000 yen = 4,500,000 yen. For development period, Company A's 100 days is shorter than Company B's 150 days, and for development cost, Company A's 4,000,000 yen is also lower than Company B's 4,500,000 yen. Therefore the combination that is 'Company A' for both period and cost, choice ア, is correct. Comparing by cost per program gives the same conclusion: Company A is 2 days × 40,000 yen = 80,000 yen while Company B is 3 days × 30,000 yen = 90,000 yen, so Company A is cheaper.
Incorrectイ
Choosing Company A for the development period is correct, but stating that Company B has the lower cost is wrong. Since Company A's 4,000,000 yen < Company B's 4,500,000 yen, Company A also has the lower cost.
Incorrectウ
Choosing Company A for the cost is correct, but stating Company B for the development period is wrong. Company B takes 150 days, which is longer than Company A's 100 days, so Company A has the shorter period.
Incorrectエ
This chooses Company B for both period and cost, but Company A has a period of 100 days and a cost of 4,000,000 yen, both below Company B (150 days, 4,500,000 yen). Company B is not better in any single item, so this is wrong.
ここがポイント
- In sequential (one-at-a-time) development, the development period can be simply summed as: number of programs × days required per program.
- Development cost = development period (days) × cost per day. Comparing by cost per program (days required × daily rate) is faster: Company A is 80,000 yen/program and Company B is 90,000 yen/program.
用語