Planning the job
Before work begins, the manager makes a plan.
- List the tasks: site preparation, paths, planting and so on.
- Order them: some tasks must wait for others (paths cannot be laid before the ground is levelled).
- Give days to each task and draw a bar chart: each bar starts on a day and has a length.
- Plan people, materials and machines for each task.
The last bar ends on the finish day. This chart is the plan to compare against.
Process control
Process control (also called progress control) means checking regularly that the real work follows the plan.
- Record what was actually done each day.
- Compare actual bars with planned bars.
- Find the cause of delay: rain, late material, too few workers.
- Act: add workers, work longer hours, change the order of tasks, or tell the client about a new finish day.
A delay in one task moves all tasks that come after it. That is why small delays must be caught early.
Quality control
Quality control checks that the finished work meets the standard in the drawing.
- Standard: for example, concrete 100 mm thick.
- Tolerance: the allowed difference, for example plus or minus 10 mm. So 90 to 110 mm passes.
- Measure with a ruler, level, measuring tape or test.
- Check materials before use (right size, right strength, no damage).
- Record every check. If it fails, redo or repair before the next layer covers it.
Safety management
Safety management protects workers and the public.
- Personal protection: helmet, gloves, boots, glasses, ear protection.
- Site layout: fences and cones round machines and holes, clear paths for people.
- Signs and talks: warning signs, short safety talks before work.
- Safe methods: trained operators, ladders and tools in good condition, first-aid kit.
- Risk check: look for dangers before each task (hole, electric line, falling objects).
No task is so urgent that it can be done unsafely.
Try it: plan a small job
Plan a job at school: clean a corner, lay a path, plant five plants. Write three tasks with days and draw the bars. Next, imagine rain delays the path by 2 days. How does the finish day change? In the 3D above, use the delay slider and the extra-crew button.
Key formulas and definitions
- Plan = tasks + order + days + resources
- Finish day = sum of days of tasks in sequence + delays
- Tolerance: standard plus or minus allowed difference
- Three controls: time (process), quality, safety
Worked examples
1. Three tasks in sequence take 3, 4 and 3 days. The second task is delayed by 2 days. When does the project end?
Planned: 3 + 4 + 3 = 10 days. With a 2-day delay the later task also moves: 3 + 6 + 3 = 12 days.
2. A slab must be 100 mm thick, tolerance plus or minus 10 mm. Readings are 92, 104 and 112 mm. Which pass?
The allowed range is 90 to 110 mm. 92 passes, 104 passes, 112 fails.
3. An extra crew cuts the path job by 2 days. With the 2-day delay, what is the finish day?
Path takes 4 + 2 - 2 = 4 days. Total 3 + 4 + 3 = 10 days. The delay is recovered.
4. Give three safety measures for a digger working beside a path.
Fence or cone off the digger area, a trained operator with a signaller, and warning signs. Workers also wear helmets and boots.
Common mistakes
- Thinking a small delay does not matter. Tasks that follow it all move.
- Measuring quality only at the end. A wrong layer is hidden once the next layer is placed.
- Forgetting tolerance. No work is exactly the standard, so the allowed range must be stated.
- Putting speed before safety.