Job Sequencing & Shop Scheduling by Hand: FCFS, SPT, EDD, Critical Ratio, Weighted Rules, Johnson's Rule & Changeover Matrices

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn a list of open jobs into start and completion times on one machine, find each job's latest start, the mean flow time of first-come-first-served and the most urgent job.
• Rank the same eight jobs by shortest processing time and by earliest due date, compute every completion time with SUMIF on the ranking and compare the mean flow time of FCFS, SPT and EDD.
• Compute lateness and tardiness for every job under SPT and EDD, then compare total tardiness, the number of late jobs and the maximum lateness of both rules.
• Compute the critical ratio of every waiting job from its due date and remaining work, rank the jobs into a dispatch list, label each one as past due, behind or on track and see how a job's ratio falls while it waits.
• Give every job a weight for its importance, sequence by processing time per weight point (WSPT), compute weighted completion and weighted tardiness and compare WSPT with plain SPT.
• Sequence six jobs that pass a saw and then a machining centre with Johnson's rule, build the two-machine timetable with MAX, and compare the makespan and the idle time with the arrival order.
• Look up sequence-dependent changeover times from a from-to matrix with INDEX/MATCH, total two colour plans, find the nearest next colour with MINIFS and measure how much a light-to-dark order saves.
• Complete a comparison of FCFS, SPT and EDD for six new jobs, pick the rule that fits the goal, schedule the jobs in EDD order and draw the plan as a stacked-bar Gantt chart.