ABC INVENTORY CONTROL MANAGEMENT AND QUALITY SERVICE DELIVERY OF SELECTED MANUFACTURING COMPANIES IN SOUTH WEST NIGERIA.

Abstract

Effective inventory management plays a vital role in ensuring operational efficiency and quality 
service delivery in manufacturing. This study explores the relationship between Activity-Based 
Classification (ABC) inventory control and service delivery performance in selected manufacturing 
companies in South West Nigeria. The research was guided by two research questions, focusing on 
how the periodic inventory system influences responsive customer support in South West, Nigeria, 
and how Just-in-Time (JIT) inventory management impacts on-time delivery in South West Nigeria. 
Anchored on Systems Theory, the study employed a quantitative research design. Data were obtained 
from 300 purposively selected respondents across inventory, logistics, and customer service 
departments in the targeted firms. A structured questionnaire served as the primary instrument for 
data collection. To ensure the validity, the instrument was reviewed by domain experts. A pilot study 
involving 30 non-sample respondents was conducted to test reliability. The instrument yielded a 
Cronbach’s Alpha of 0.83, confirming strong internal consistency. Data were analyzed using SPSS 
version 26, applying inferential statistics of Pearson correlation. Results reveal a significant positive 
relationship between the periodic inventory system and responsive customer support (r = 0.856, p = 
0.032), suggesting that well-managed periodic reviews contribute to improved customer 
responsiveness. Additionally, a very strong and statistically significant correlation was found between 
JIT inventory management and on-time delivery (r = 0.976, p = 0.020), highlighting the efficiency of 
JIT practices in meeting delivery timelines. The findings underscore the need for manufacturing firms 
to strategically align inventory management practices with customer service objectives to boost 
competitiveness and service quality. The study recommends the adoption of technology-enhanced 
periodic inventory systems and the integration of JIT practices tailored to each firm’s operational 
structure and market demands. These measures are essential for improving responsiveness, reducing 
inefficiencies, and achieving sustainable service excellence.