A system study on the production system of Hi-Top Plastic Manufacturing

Date of Publication


Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Industrial Engineering


Gokongwei College of Engineering


Industrial Engineering

Thesis Adviser

Dennis E. Cruz

Defense Panel Chair

Rosemary R. Seva

Defense Panel Member

Willy F. Zalatar


Hi-Top Plastic Manufacturing is a plastic manufacturing company that provides mass production of certain plastic products that are used everywhere. The company aims to be inclined in satisfying the wants and needs of the customers by providing competitively-priced high-quality products, services and by delivering on-time and envisions to be the first choice of the customers in selecting a manufacturer of plastic products. The company is strategically located in Caloocan City, which is not too far away from the National Capital Region (NCR).

Their system was evaluated in terms of its man, material, machine, and method (4Ms). Based on this system evaluation, strengths, weaknesses, opportunities, and threats were identified. After listing those down, the weaknesses, opportunities, and threats were then assessed by utilizing historical data and observed data. As such, it was determined that the weaknesses of the system include there is an average reject of 2.7% which exceeds the acceptable reject rate of 1.0% by 1.7%, the systems machine utilization averaged at a monthly rate of 42.6% which deviates from the target utilization of 60% by 17.4%, and the system experienced a monthly average of 3.8% in waste raw materials which deviates from the standard allowable waste allowance by exactly 0.8%. moreover, the opportunity that the system can grab are the utilization of recycled resin from grinded wastes or rejected products in production, utilize a more efficient model design to require 30% less plastic, and to introduce a new product category containing beach utilities. And lastly, the threat is the possibility of a labor strike. From these listed weaknesses, opportunities, and threat, all seven statements were ranked in order terms of their weighted total score. Thus the most problematic was deemed to be its weakness of its reject rate.

During the period of August 2016 to July 2017, the company was not able to meet the target reject rate by 1.7% which resulted to a reject cost of ±3,802,259.47. after evaluating the probable causes of the problem, the final causes were determined using the historical data and work sampling and plotted in the fishbone diagram. As such the final causes for the machine includes: machine overheat (2.6%), damaged centralized cooling (5.4%), power interruptions (1.3%), and damaged injection machine (1.7%). Moreover, the final causes for material are dampness level of resin (10.7%) and incorrect ration recycled and virgin resins (1.3%). Lastly, the final causes for method are the insufficient cleaning procedure (52.8%), ineffective cutting procedure (14.8%), unable to set pressure and temperature parameters (5.5%), and unintentional wrong parameters set (4.8%). However, since only 63.0% is needed to be reduced from the reject rate to reach the standard 1.0%, only the dampness level of resins, insufficient cleaning procedure, and ineffective cutting procedure are considered because these already comprises about 77.3%.

The proposed solutions to improve the company's system include: for insufficient cleaning procedure, it is to perform purging incorporated with Colella and Wormers method of cleaning infection machine barrels and screws in between color changes. For ineffective cutting procedure, it is to purchase a new fixture to hold the plastic for trimming. For the dampness level of resins, it is to increase the hopper dryer temperature. The computed net present value for the proposed system in a year is ±2,286,579.66. it would give a return on investment of 0.35 or 35.26% and a payback period of 2.84 months, which is equivalent to roughly 3 months. Moving on, the recommendation for future studies would be the other seven causes not tackled in this study as they could possibly further decrease the reject rate.

Abstract Format






Accession Number


Shelf Location

Archives, The Learning Commons, 12F, Henry Sy Sr. Hall

Physical Description

iv, 216 leaves : illustrations (some color) ; 29 cm.


Industrial engineering; Hi-Top Plastic Manufacturing

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