CASE STUDY $6\mathrm{.}1$

Johnston Products

No matter how many times Justin Wang, the master scheduler for Johnston Products, tried, he couldn't seem to get it through people's minds. They kept trying to 'front load" the production schedule by attempting to catch up with production they failed to make the previous week, and the problem appeared to be getting worse. It seemed to happen every week, and the only way Justin could get things back to a realistic position was to completely reconstruct the entire master schedule$-$usually about every three weeks.

Last month could serve as an example. The first week of the month Justin had scheduled production equal to $320$ standard hours in the assembly area. The assembly area managed to complete only $291$ hours that week because of some equipment maintenance and a few unexpected part shortages. The assembly supervisor then bad the workers complete the remaining $29$ hours from week $1$ at the start of week $2.$ Siner week $2$ already had $330$ standard hours scheduled, the additional $29$ hours really put them in a position of attempting to complete $359$ hours. The workers actually completed $302$ hours in week $2,$ leaving

Production Activity Control

$163$

$57$ hours to front load into week $3,$ and so forth. Usually by the time Justin came to his three$-$week review of the master schedule, it was not uncommon for the assembly area to be more than $100$ standard hours behind schedule.

Clearly, something needed to be done. Justin decided to review some of the areas that could be causing the problem:

Job standards Although it had been at least four years since any job standards had