Manpower Indentation for the New Apron Gate Complex
You are the assistant manpower clerk preparing an indentation for a newly built apron gate complex at a Category B airport. The complex requires six manned posts for 24 hours a day, seven days a week: main vehicle gate, pedestrian gate, cargo gate, patrol post, control room and escort standby. Each post is manned by one person per 8-hour shift. Each person works six days a week with one weekly off, and is entitled to 30 days annual leave, 12 casual leave days and 10 public holidays a year; average absence for sickness, training and courses is a further 8% of the remaining working days. The sanctioned strength of the complex is 22, of whom 3 are away on a 90-day basic course until the end of the quarter. From next quarter the main vehicle gate must be doubled between 06:00 and 18:00. The station commander wants the requirement, the shortfall and the additional posts to be sanctioned, with the calculation shown.
1. Compute the manpower required for the present six-post configuration and the actual shortfall today.
Read the worked answer
Step 1 - man-shifts per day: 6 posts × 3 shifts = 18 man-shifts/day. Step 2 - man-shifts per year: 18 × 365 = 6,570. Step 3 - net shifts one person can give:
- Days in the year: 365
- Less weekly offs (one per week): −52
- Less annual leave: −30
- Less casual leave: −12
- Less public holidays: −10
- Remaining working days: 261
- Less 8% average absence: 261 × 0.92 = 240.12 → 240 shifts per person per year. Step 4 - requirement: 6,570 ÷ 240 = 27.375 → round up, because a fraction of a man cannot man a post: 28 personnel. Step 5 - availability today: 22 sanctioned − 3 on course = 19. Shortfall: 28 − 19 = 9 personnel today. Note the difference between the two figures: the sanctioned strength itself is 6 short of the true requirement (28 − 22), and the day-to-day gap is 9 because of the course.
2. Recompute the requirement once the main vehicle gate is doubled from 06:00 to 18:00, and state what should be asked for.
Read the worked answer
Extra load: 06:00–18:00 is 12 hours, i.e. 1.5 shift-slots of 8 hours, needing one extra person throughout: +1.5 man-shifts/day. New daily total: 18 + 1.5 = 19.5 man-shifts/day. Annual: 19.5 × 365 = 7,117.5 man-shifts. Requirement: 7,117.5 ÷ 240 = 29.65 → 30 personnel. What to ask for:
- Sanctioned strength raised from 22 to 30 - that is 8 additional posts.
- Until the three men return from course, the working gap is 30 − 19 = 11.
- Ask in the same indentation for a relief pool and for the doubling to be met by staggering the pedestrian gate's peak hours if sanction is delayed. Presentation point: show the arithmetic in the note. A bare figure of 30 invites the reply 'why not 18?', and an indentation that cannot be defended on paper is the one that gets cut.
3. A colleague argues the requirement is simply 6 posts × 3 shifts = 18 people. Identify the errors in that reasoning and the operational risk of under-indenting.
Read the worked answer
Errors:
- It counts posts, not people. It assumes every man is present 365 days a year, which ignores the weekly off, the 52 days of leave and the 8% absence already priced in - about one day in three.
- It ignores the round-up rule. Manpower must be a whole number and each post must be filled for the full shift; 27.375 becomes 28, never 27.
- It ignores the course and medical categories, which are real deductions from sanctioned strength on any given day. Risk of under-indenting:
- Unfilled posts are covered by doubling up or by overtime, which produces fatigue, missed screening and, at a gate, a security gap at exactly the hours when traffic is heaviest.
- Men denied leave stop asking for it, and unauthorised absence then becomes the informal relief system - a discipline problem created by the establishment table.
- Leave blocks collide in the same fortnight, so a plan that looks adequate on annual average fails in the peak month. Check the leave plan month by month before signing the indentation.