Methodology

This research used the surveying strategy, which was carried out through an anonymous, online filled questionnaire.

Scope of the study

The study was carried out in 20 humanitarian NGOs in Lebanon comprised of 200 project managers working at the different five organizational forms. The study was limited to this number of NGOs since the other NGOs were strictly confidential about their projects' performance and thus they refrained from participating in this study.

Data collection

The questionnaire was used as a main data collection and it was designed to foster quantitative data to be analyzed statistically using SPSS v25.

Design of the data collection technique

The design of the questionnaire followed the objectives of the research. Accordingly, project managers were asked to rank their level of agreement with the below:

(i) Problems facing projects' implementation (Project planning problems, Structural problems, lack of necessary expertise problems in addition to external problems) Projects meeting their time, cost and technical performance.
(ii) The relative influence of the planning, structural, technical expertise in addition to external factors on the projects' overall performance.

Sampling and sample size determination

The 200 project managers in this study were desegregated into clusters according to the five organizational types as depicted in Table 1. Systematic sampling was administered to the homogenous strata in an attempt to obtain the most representative sample. According to Bradley, systematic sampling allows the researcher to select sample at regular intervals, requiring calculating the sampling proportion to be able to obtain the sample from each cluster (Bradley, 1999). The actual sample size was determined through the table developed by Bartlett, Kotrlik and Higgins who provided sample size determination for both categorical and continuous data.

For a population size of 200 project managers considering a 5% margin of error, the minimum sample size is 132 project managers to be selected from the different organizational type using systematic sampling (Table 1).

Table 1. Sample size of the population
Cluster or sample frame
 (Total number of project managers by clusters)
 Population Sample proportion
 Sample size
Mechanistic organizational structure
 Functional
Weak matrix
Balanced matric
 35
35
30
 0.175
0.175
0.15
 23
23
20
Organic organizational structure
 Strong matrix
Project-based
 50
50
 0.25
0.25
 33
33
Total
200 1 132

Data analysis techniques

(1) Descriptive statistics used to determine the mean and standard deviations of the respondent's agreements with the questionnaire's components.

(2) Pearson Product Moment Correlation used to determine the influence of each factor listed in this study on the project's overall performance.

(3) Multiple regression analysis used to delineate the influence among the factors in the study and their significance to the project's overall performance when being integrated all together.